Evaporative emission system diagnosis for gtdi engines using an electric supercharger

Abstract

Methods and systems are provided for diagnosing a vehicle fuel system and an evaporative emission system, and for diagnosing components in the evaporative emission system. In one example, a method includes activating an electric compressor to evacuate the fuel system and the evaporative emission system when an engine propelling a vehicle is not in operation, sealing the fuel system and the evaporative emission system in response to a threshold vacuum being reached during the evacuation, and indicating a presence or absence of non-significant undesirable evaporative emissions based on a pressure rise in the sealed fuel system and evaporative emission system. In this way, a source of undesirable evaporative emissions can be readily detected so that release of undesirable evaporative emissions to the environment can be reduced.

Description

TECHNICAL FIELD

[0001] The present description relates generally to methods and systems for diagnosing undesirable evaporative emissions of a vehicle fuel system and evaporative emissions system, where the vehicle includes an electronic supercharger.

[0002] BACKGROUND / SUMMARY

[0003] Vehicles can be equipped with evaporative emission control systems, such as on-board fuel vapor recovery systems. Such systems capture evaporated hydrocarbons and prevent their release into the atmosphere, such as fuel vapors generated in a vehicle's gasoline tank during refueling. Specifically, evaporated hydrocarbons (HC) are stored in a fuel vapor canister filled with adsorbent that adsorbs and stores the vapors. Later, when the engine is in operation, the evaporative emission control system allows the vapors to be purged into the engine intake manifold for use as fuel. The fuel vapor recovery system can include one or more check valves, injectors, and / or controller-actuatable valves to facilitate purging of stored vapors under supercharged or non-supercharged engine operation.

[0004] Various methods have been developed for detecting undesirable fuel vapor evaporative emissions and / or degraded components in such fuel vapor recovery systems. However, the inventors have recognized certain potential problems with these methods. The inventors have recognized that it can be particularly difficult to diagnose one or more check valves located in the evaporative emission control system during vehicle operation under supercharged or non-supercharged conditions. For example, under non-supercharged conditions (e.g., naturally aspirated), it can be difficult to determine whether a first check valve located downstream of a canister purge valve (CPV) and upstream of an intake manifold of an engine is stuck closed or whether significant undesirable evaporative emissions exist in the evaporative emission control system. Further, under supercharged conditions, it can be similarly difficult to determine whether a second check valve located downstream of the CPV and upstream of an injector and intake passage is stuck closed or whether significant undesirable evaporative emissions exist in the evaporative emission control system. More specifically, under non-supercharged conditions, a stuck closed first check valve can be incorrectly interpreted as significant undesirable evaporative emissions. Alternatively, under supercharged conditions, significant undesirable evaporative emissions can be incorrectly interpreted as a stuck closed second check valve.

[0005] Further, in certain types of vehicles, such as hybrid electric vehicles (HEVs) and plug-in HEVs (PHEVs), engine run time can be limited, and thus techniques that rely on heat consumption from the engine, such as engine off natural vacuum (EONV), cannot be used to test for the presence or absence of non-significant undesirable evaporative emissions from the vehicle's evaporative emission system and / or fuel system. To circumvent this problem, a vacuum pump can be incorporated into the vehicle system to test for non-significant undesirable evaporative emissions. However, this pump adds weight, cost, etc., and its use can not resolve the diagnostics discussed above in the boosted and non-boosted conditions. The inventors have recognized these problems herein.

[0006] Accordingly, the inventors have developed herein systems and methods to at least partially address the above problems. In one example, a method is provided that includes, under predetermined conditions, supplying air from an electric compressor to an engine propelling a vehicle; evacuating a fuel system and an evaporative emission system of the vehicle to a threshold vacuum by activating the electric compressor when the engine is off; and indicating the presence or absence of non-significant undesirable evaporative emissions based on a pressure rise in the fuel system and the evaporative emission system after the threshold vacuum is reached. In this way, the presence of non-significant undesirable evaporative emissions can be diagnosed during an engine off condition without the need for additional components such as the vacuum pump mentioned above.

[0007] In one example, such a method can include indicating the absence of significant undesirable evaporative emissions in the fuel system and the evaporative emission system and indicating that a second check valve located upstream of an injector system is functioning as needed in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emission system via activation of the electric compressor. In response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emission system, in one example, such a method can include subsequently evacuating the fuel system and the evaporative emission system under conditions of negative pressure in an air intake of the engine with the electric compressor being off, and indicating that a first check valve located upstream of the air intake is functioning as needed in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emission system under conditions of negative pressure. In this way, it is possible to robustly and accurately diagnose the presence or absence of significant undesirable evaporative emissions, as well as whether the first and / or second check valves are functioning as needed. The above described advantages and other advantages and features of the present description will be apparent from the following detailed description when considered in conjunction with the drawings, which are illustrative only and are not intended to limit the present description to the exact arrangements and configurations depicted. The above and other advantages of the present description can be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

[0008] It is to be understood that the above general description is intended to be illustrative only and not restrictive. Many embodiments of the application are readily obvious upon consideration of the above description. Accordingly, the phraseology or terminology employed herein, and not otherwise specifically defined, is for the purpose of description only and is not intended to be limiting. The use of outlining headings and subheadings are intended to aid reading of the disclosure and should not be interpreted as in any way limiting. Furthermore, it is intended that the scope of the application encompass all such alterations and modifications of the inventive concept as fall within the scope of the appended claims. Applicants reserve the right to amend the claims to affirmatively disclaim non-essential features of the application as further described herein. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 A schematic diagram of a multi-path fuel vapor recovery system of a vehicle system is shown.

[0010] Figure 2 A high level block diagram showing an example vehicle system is shown.

[0011] Figure 3 A high level flowchart of an example method for testing for undesirable evaporative emissions on a fuel system and an evaporative emissions system via an electric supercharger during an engine off condition is shown.

[0012] Figure 4 A high level flowchart of an example method for testing for undesirable evaporative emissions on a fuel system and an evaporative emissions system during a supercharged engine operation in which an engine is operated to combust air and fuel is shown.

[0013] Figure 5 A high level example method for testing for undesirable evaporative emissions on a fuel system and an evaporative emissions system via spinning an engine without fueling is shown.

[0014] Figure 6 A high level example method for testing for undesirable evaporative emissions on a fuel system and an evaporative emissions system via natural intake air when an engine is operating to combust air and fuel is shown.

[0015] Figure 7 A high level example method for utilizing Figures 3 to 6 A high level example method for dual test monitoring of a vehicle evaporative emissions system using the method shown.

[0016] Figure 8 An example lookup table stored at a vehicle controller for determining Figure 7 the results of dual test monitoring.

[0017] Figure 9 A high level example method for performing a fuel vapor filter canister purge operation dependent on Figure 7 the results of dual test monitoring.

[0018] Figure 10 A high level example method for determining Figure 7Example timeline for dual-test monitoring.

[0019] Figure 11 It shows the method for obtaining Figure 7 The example timeline shown is the result of a fuel vapor filter flushing operation following dual test monitoring. Detailed Implementation

[0020] The following description relates to systems and methods for performing one or more tests to detect the presence or absence of unwanted evaporative emissions in a vehicle's fuel system and evaporative emission system, and for diagnosing components in the evaporative emission system based on the results of one or more tests. Testing for the presence or absence of unwanted evaporative emissions can be performed on vehicle systems including dual-path flushing systems (such as...). Figure 1 The washing is performed on the vehicle system shown, and the dual-path flushing system has an injector system and an electric supercharger. Figure 1 The vehicle system shown may include a hybrid electric vehicle system, such as Figure 2 The vehicle system is shown. In one example, one or more tests may include an engine-off boost evaporative emission test, which may utilize an electric supercharger to generate positive intake pressure relative to atmospheric pressure. This positive pressure can be transmitted to the injector system, which may evacuate the vehicle's fuel system and evaporative emission system (to a negative pressure relative to atmospheric pressure) to... Figure 3 This indicates the presence or absence of unwanted evaporative emissions. In another example, this can be performed while the engine is operating to burn air and fuel. Figure 3 The test shown is similar to other tests, such as Figure 4 The method is shown in the figure.

[0021] In another example, according to Figure 5 The method may include one or more tests that could involve evacuating the fuel system and evaporative emission system via natural air intake, wherein the engine spins without fuel to generate negative pressure in the engine's intake manifold, said negative pressure being used to evacuate the fuel system and evaporative emission system. In yet another example, according to Figure 6 The method may include one or more tests that may include evacuating the fuel system and evaporative emission system via natural air intake, wherein the engine is operating and burning air and fuel, which may generate negative pressure in the engine's intake manifold, said negative pressure being used to evacuate the fuel system and evaporative emission system.

[0022] according to Figure 7 The method can be used in various combinations. Figures 3 to 6The illustrated method is to perform a dual test monitoring that can enable determination of whether significant or non-significant undesirable evaporative emissions exist in the fuel system and evaporative emissions system, and whether one or more components (e.g., check valves) in the evaporative emissions system are functioning as desired. The results of this test can be interpreted via a lookup table stored at the controller of the vehicle, such as Figure 8 The illustrated lookup table to interpret the results of this test.

[0023] In some examples, in accordance with Figure 9 The illustrated method, in response to an indication that one or the other of one or more check valves in the evaporative emissions system is stuck closed, a fuel vapor canister purge operation can be timely performed in order to ensure robust emptying of the fuel vapor canister. Figure 10 A timeline for performing Figure 7 The illustrated dual test monitoring. Figure 11 A timeline for timely performing a fuel vapor canister purge operation in accordance with Figure 9 The illustrated dual test monitoring.

[0024] Turning to the drawings, Figure 1 A schematic view of a vehicle system 100 is illustrated. The vehicle system 100 includes an engine system 102 coupled to a fuel vapor recovery system (evaporative emissions control system) 154 and a fuel system 106. The engine system 102 can include an engine 112 having a plurality of cylinders 108. In some examples, the vehicle system can be configured as a hybrid electric vehicle (HEV) or a plug-in HEV (PHEV). Accordingly, an on-board energy storage device 250 can be included in the vehicle system 100. The on-board energy storage device 250 can include a high voltage battery, a capacitor, a super capacitor, etc. Figure 2 Details of components and operating conditions related to hybrid vehicle operation will be discussed in detail. The engine 112 includes an engine air intake 23 and an engine exhaust 25. The engine air intake 23 includes a throttle valve 114 fluidly coupled to an engine intake manifold 116 via an intake passage 118. An air cleaner 174 is located upstream of the throttle valve 114 in the intake passage 118. The engine exhaust 25 includes an exhaust manifold 120 leading to an exhaust passage 122 that carries exhaust gas to the atmosphere. The engine exhaust 122 can include one or more emission control devices 124 that can be installed in close coupled locations in the exhaust. The one or more emission control devices can include a three-way catalyst, a lean NOx trap, a diesel particulate filter, an oxidation catalyst, etc. It will be appreciated that other components such as various valves and sensors can be included in the vehicle system as set forth further below.

[0025] The throttle 114 can be located in an intake passage 118 downstream of a compressor 126 of a supercharging device, such as a turbocharger 50 or a mechanical supercharger. The compressor 126 of the turbocharger 50 can be arranged between an air cleaner 174 and the throttle 114 in the intake passage 118. The compressor 126 can be at least partially powered by an exhaust turbine 54 arranged between an exhaust manifold 120 and an emission control device 124 in an exhaust passage 122. The compressor 126 can be coupled to the exhaust turbine 54 via a shaft 56. The compressor 126 can be configured to draw intake air into an air intake system (AIS) 173 at atmospheric pressure and supercharge it to a higher pressure. Using the supercharged intake air, supercharged engine operation can be performed.

[0026] The amount of supercharging can be at least partially controlled by controlling the amount of exhaust gas directed through the exhaust turbine 54. In one example, when a greater amount of supercharging is requested, a greater amount of exhaust gas can be directed through the turbine. Alternatively, for example, when a lesser amount of supercharging is requested, some or all of the exhaust gas can be bypassed around the turbine via a turbine bypass passage as controlled by a wastegate (not shown). Additionally or alternatively, the amount of supercharging can be controlled by controlling the amount of intake air directed through the compressor 126. The controller 166 can adjust the amount of intake air drawn through the compressor 126 by adjusting a position of a compressor bypass valve (not shown). In one example, when a greater amount of supercharging is requested, a lesser amount of intake air can be directed through the compressor bypass passage.

[0027] Although turbochargers (e.g., 50) are commonly used in turbocharged gasoline direct injection (GTDI) vehicles to enhance power to the driven wheels, in some examples there can be a time delay between a request for supercharged operation and delivery of torque. More specifically, since power from a turbocharger can utilize waste heat from an exhaust system, there can be a delay in turbo spooling as it can take time for torque from exhaust pressure onto the exhaust turbine to first overcome rotational inertia of the turbocharger assembly, as well as friction and compressor load.

[0028] To assist the turbocharger, an electrically powered supercharger 155 (eBooster) can be incorporated into the vehicle propulsion system. The electrically powered supercharger 155 can be powered via an on-board energy storage device 250, which can include a battery, a capacitor, a super capacitor, etc. In one example, the electrically powered supercharger 155 can be activated (actuated on) in response to a demand for wheel torque in order to quickly provide the engine with the desired charge air without the delay that can occur with the turbocharger 50 alone. In this example, the electrically powered supercharger 155 can be actuated off or deactivated in response to the turbocharger accelerating to a threshold speed (e.g., 70,000 rpm). More specifically, the operation control of the electrically powered supercharger 155 can be under the control of a vehicle controller (e.g., 166). For example, the controller can send a signal to the electrically powered supercharger actuator 155b that can actuate the electrically powered supercharger on. In another example, the controller can send a signal to the electrically powered supercharger actuator 155b that can actuate the electrically powered supercharger off. In one example, the electrically powered supercharger actuator can include a motor that drives the compression of air.

[0029] The electrically powered supercharger 155 can be located between a first electrically powered supercharger conduit 159a and a second electrically powered supercharger conduit 159b. The first electrically powered supercharger conduit 159a can fluidly couple the intake passage 118 to the electrically powered supercharger 155 upstream of the electrically powered supercharger bypass valve 161. The second electrically powered supercharger conduit 159b can fluidly couple the electrically powered supercharger 155 to the intake passage 118 downstream of the electrically powered supercharger bypass valve 161. By way of example, air can be drawn into the electrically powered supercharger 155 via the first electrically powered supercharger conduit 159a upstream of the electrically powered supercharger bypass valve 161, and the compressed air can exit the electrically powered supercharger 155 and be carried to the intake passage 118 via the second electrically powered supercharger conduit downstream of the electrically powered supercharger bypass valve 161. In this manner, compressed air can be carried to the engine intake 23.

[0030] In the event that the electrically powered supercharger 155 is activated to provide charge more quickly than relying on the turbocharger 50 alone, it can be appreciated that the electrically powered supercharger bypass valve 161 can be commanded closed while the electrically powered supercharger 155 is activated. In this manner, intake air can flow through the turbocharger 50 and through the electrically powered supercharger 155. Once the turbocharger reaches a threshold speed, the electrically powered supercharger 155 can be closed, and the electrically powered supercharger bypass valve 161 can be commanded open.

[0031] The fuel system 106 can include a fuel tank 128 coupled to a fuel pump system 130. The fuel pump system 130 can include one or more pumps for pressurizing fuel delivered to fuel injectors 132 of the engine 112. Although only a single fuel injector 132 is shown, additional injectors can be provided for each cylinder. For example, the engine 112 can be a direct injection gasoline engine and additional injectors can be provided for each cylinder. It will be appreciated that the fuel system 106 can be a returnless fuel system, a return fuel system, or various other types of fuel systems. In some examples, the fuel pump can be configured to draw liquid from the tank off the tank bottom. Vapor generated in the fuel system 106 can be transported via a conduit 134 to a fuel vapor recovery system (evaporative emission control system) 154 described further below before being purged to the engine air intake 23.

[0032] The fuel vapor recovery system 154 includes a fuel vapor holding or fuel vapor storage device, shown herein as a fuel vapor canister 104. The canister 104 can be filled with a sorbent capable of binding a large amount of evaporated HC. In one example, the sorbent used is activated carbon. The canister 104 can include a buffer 104a (or buffer region) and a non-buffer region 104b, each of which includes sorbent. The sorbent in the buffer 104a can be the same or different than the sorbent in the non-buffer region 104b. As shown, the volume of the buffer 104a can be less than (e.g., a fraction of) the volume of the non-buffer region 104b. The buffer 104a can be located within the canister 104 such that during canister loading, fuel tank vapor is first adsorbed within the buffer, and then when the buffer is saturated, other fuel tank vapor is adsorbed in the non-buffer region 104b of the canister 104. In contrast, during canister purging, fuel vapor can be first desorbed from the non-buffer region 104b (e.g., to a threshold amount) before being desorbed from the buffer 104a. In other words, the loading and unloading of the buffer is not linear with the loading and unloading of the non-buffer region. Thus, the effect of the canister buffer is to prevent any fuel vapor plume from flowing from the fuel tank to the canister, thereby reducing the likelihood of any fuel vapor plume going to the engine.

[0033] The canister 104 can receive fuel vapor from the fuel tank 128 via a conduit 134. Although the illustrated example shows a single canister, it will be appreciated that in alternative embodiments, multiple such canisters can be connected together. The canister 104 can be in communication with the atmosphere via a vent line 136. In some examples, a canister vent valve 172 can be positioned along the vent line 136, coupled between the fuel vapor canister and the atmosphere, and can adjust the flow of air and vapor between the canister 104 and the atmosphere. However, in other examples, the canister vent valve can not be included. In one example, the operation of the canister vent valve 172 can be regulated by a canister vent solenoid (not shown). For example, the canister vent valve can be opened or closed based on whether the canister is to be purged. In some examples, an evaporative level check monitor (ELCM) (not shown) can be disposed in the vent line 136 and can be configured to control venting and / or assist in detection of undesirable evaporative emissions. Further, in some examples, one or more oxygen sensors can be located in the engine air intake 116, or coupled to the canister 104 (e.g., downstream of the canister) to provide an estimate of the canister loading. In other examples, one or more temperature sensors 157 can be coupled to and / or within the canister 104. As will be discussed in further detail below, when fuel vapor is adsorbed by the adsorbent in the canister, heat is generated (heat of adsorption). Likewise, when fuel vapor is desorbed by the adsorbent in the canister, heat is consumed. In this way, the adsorption and desorption of fuel vapor by the canister can be monitored and estimated based on temperature changes within the canister, and can be used to estimate the canister loading.

[0034] The conduit 134 can optionally include a fuel tank isolation valve (not shown). Among other functions, the fuel tank isolation valve can allow the fuel vapor canister 104 to be maintained at a low pressure or vacuum without increasing the rate of fuel evaporation from the tank (which would otherwise occur as the fuel tank pressure is reduced). The fuel tank 128 can contain a variety of fuel mixtures, including fuels having a range of alcohol concentrations, such as various gasoline-ethanol mixtures, including E10, E85, gasoline, etc., and various combinations thereof.

[0035] The fuel vapor recovery system 154 can include a dual path purge system 171. The purge system 171 is coupled to the canister 104 via a conduit 150. The conduit 150 can include a canister purge valve (CPV) 158 disposed therein. As discussed herein, the CPV 158 can be referred to as a first CPV (CPV1) 158. In particular, the CPV1 158 can regulate the flow of vapor along the conduit 150. The amount and rate of vapor released by the CPV1 158 can be determined by the duty cycle of an associated CPV1 solenoid (not shown). In one example, the duty cycle of the CPV1 solenoid can be determined by the controller 166 in response to engine operating conditions, including, for example, air-to-fuel ratio. By commanding the CPV1 to close, the controller can seal the fuel vapor canister from the fuel vapor purge system such that vapor is not purged via the fuel vapor purge system. Conversely, by commanding the CPV1 to open, the controller can enable the fuel vapor purge system to purge vapor from the fuel vapor canister.

[0036] The fuel vapor canister 104 operates to store evaporated hydrocarbons (HC) from the fuel system 106. In some operating conditions, such as during refueling, when liquid is added to the fuel tank, fuel vapor present in the fuel tank can be displaced. The displaced air and / or fuel vapor can be carried from the fuel tank 128 to the fuel vapor canister 104 and then to the atmosphere via the vent line 136. In this manner, an increased amount of evaporated HC can be stored in the fuel vapor canister 104. During later engine operation, the stored vapor can be released back into the incoming air charge via the fuel vapor purge system 171.

[0037] In some examples, an air intake system hydrocarbon trap (AIS HC) 169 can be placed in the intake manifold of the engine 112 to adsorb fuel vapor emitted from unburned fuel in the intake manifold, stirred fuel from a leaking injector, and / or fuel vapor in the crankcase ventilation discharge during engine off periods. The AIS HC can include a stack of successive layers of polymer sheets infused with HC vapor adsorption / desorption material. Alternatively, the adsorption / desorption material can fill the area between the layers of polymer sheets. The adsorption / desorption material can include one or more of carbon, activated carbon, zeolite, or any other HC adsorption / desorption material. When the engine is in operation resulting in an intake manifold vacuum and resulting air flow across the AIS HC, the trapped vapor is passively desorbed from the AIS HC and combusted in the engine. Thus, during engine operation, intake fuel vapor is stored and desorbed from the AIS HC 169. Additionally, fuel vapor stored during engine off periods can also be desorbed from the AIS HC during engine operation. In this way, the AIS HC 169 can be constantly loaded and purged, and the trap can reduce evaporative emissions from the intake tract even when the engine 112 is off.

[0038] The conduit 150 is coupled to the injector 140 in the injector system 141 and includes a second check valve (CV2) 170 disposed in the conduit 150 between the injector 140 and the CPV1 158. The second check valve (CV2) 170 can prevent incoming air from flowing into the conduit 150 from the injector while allowing air and fuel vapor to flow from the conduit 150 into the injector 140. The CV2 170 can be, for example, a vacuum-actuated check valve that opens in response to a vacuum drawn from the injector 140.

[0039] The conduit 151 couples the conduit 150 to the intake port 23 at a location within the conduit 150 between the CV2 170 and the CPV1 158 and at a location downstream of the throttle 114 in the intake port 23. For example, the conduit 151 can be used to direct fuel vapor from the canister 104 to the intake port 23 during a purge event using a vacuum created in the intake manifold 116. The conduit 151 can include a first check valve (CV1) 153 disposed therein. The first check valve (CV1) 153 can prevent incoming air from flowing into the conduit 150 from the intake manifold 116 while allowing fluid and fuel vapor to flow from the conduit 150 into the intake manifold 116 via the conduit 151 during a canister purge event. The CV1 can be, for example, a vacuum-actuated check valve that opens in response to a vacuum drawn from the intake manifold 116.

[0040] The conduit 148 can be coupled to the first port or inlet 142 of the ejector 140. The ejector 140 includes a second port 144 or inlet that couples the ejector 140 to the conduit 150. The ejector 140 is coupled to the intake 23 via the conduit 148 at a location upstream of the throttle 114 and downstream of the compressor 126. During a boost condition, the conduit 148 can direct compressed air in the intake conduit 118 downstream of the compressor 126 into the ejector 140 via the port 142.

[0041] In some examples, a second canister purge valve (CPV2) 165 can be configured to selectively fluidly couple to the conduit 150 downstream of the CPV1 158 and to the vent line 136 upstream of the fuel vapor canister 104. More specifically, a conduit 163a (first conduit 163a) can fluidly couple the CPV2 165 to the conduit 150 (purge conduit 150) downstream of the CPV1 158, and a conduit 163b (second conduit 163b) can fluidly couple the CPV2 165 to the vent line 136 between the CVV 172 and the fuel vapor canister 104. The operation of the CPV2 165 and the conditions for operating the CPV2 165 will be discussed in detail below. Briefly, the CPV2 can be regulated by a CPV2 solenoid (not shown), where a command from a controller 166 of the vehicle to the CPV2 solenoid can actuate the CPV2 to open or close.

[0042] The ejector 140 can also be coupled to the intake conduit 118 at a location upstream of the compressor 126 via a shutoff valve 193. The shutoff valve 193 is directly hard mounted to the intake system 173 at a location along the conduit 118 between the air cleaner 174 and the compressor 126. For example, the shutoff valve 193 can be coupled to an existing AIS threaded interface or other aperture in the AIS 173, such as an existing SAE male quick connect port. The hard mounting can include a non-flexible direct mounting. For example, the non-flexible hard mounting can be achieved via a variety of methods including spin welding, laser welding, or adhesive. The shutoff valve 193 is configured to close in response to an undesirable emission being detected downstream of the outlet 146 of the ejector 140. As Figure 1 As shown, in some examples, a conduit or hose 152 can couple the third port 146 or outlet of the ejector 140 to the shutoff valve 193. In this example, if the shutoff valve 193 is detected to be disconnected from the AIS 173, the shutoff valve 193 can close, thus interrupting the airflow from the engine intake downstream of the compressor to the converging hole in the ejector. However, in other examples, the shutoff valve can be integrated with and directly coupled to the ejector 140.

[0043] Ejector 140 includes a housing 168 that is coupled to ports 146, 144, and 142. In one example, only three ports 146, 144, and 142 are included in ejector 140. Ejector 140 can include various check valves disposed therein. For example, in some examples, ejector 140 can include a check valve positioned adjacent to each port in ejector 140, such that there is one-way fluid or air flow at each port. For example, air from intake conduit 118 downstream of compressor 126 can be directed into ejector 140 via inlet port 142, and can flow through the ejector and exit the ejector at outlet port 146 before being directed into intake conduit 118 at a location upstream of compressor 126. This flow of air through the ejector can create a vacuum at inlet port 144 due to the Venturi effect, such that a vacuum is provided to conduit 150 via port 144 during a boost condition. In particular, a low pressure region is created adjacent to inlet port 144, which can be used to draw purge vapor from the canister into ejector 140.

[0044] Ejector 140 includes a nozzle 191 that includes an orifice that converges in a direction from inlet 142 toward suction port 144, such that a vacuum is created at port 144 due to the Venturi effect when air flows through ejector 140 in a direction from port 142 toward port 146. This vacuum can be used to assist with fuel vapor purging during certain conditions, such as during a boost engine condition. In one example, ejector 140 is a passive component. That is, ejector 140 is designed to provide a vacuum to the fuel vapor purge system via conduit 150 to assist with purging under various conditions without being actively controlled. Thus, in view of the fact that CPV1 158, CPV2 165, and throttle 114 can be controlled via, for example, controller 166, ejector 140 can be neither controlled via controller 166 nor subject to any other active control. In another example, the ejector can be actively controlled with variable geometry to adjust the amount of vacuum provided to the fuel vapor recovery system via conduit 150 by the ejector.

[0045] During selected engine and / or vehicle operating conditions, such as after an emissions control device light-off temperature has been reached (e.g., a threshold temperature reached after warm-up from ambient temperature) and as the engine operates, the controller 166 can adjust the duty cycle of the canister vent valve solenoid (not shown) and open or keep open the canister vent valve 172. For example, the canister vent valve 172 can remain open except during vacuum testing performed on the system (described in further detail below). At the same time, the controller 166 can adjust the duty cycle of the CPV1 solenoid (not shown) and open the CPV1 158. Pressure within the fuel vapor purge system 171 can then draw fresh air via the vent line 136, the fuel vapor canister 104, and the CPV1 158, such that fuel vapor flows into the conduit 150.

[0046] Operation of the ejector 140 within the fuel vapor purge system 171 during a vacuum condition will now be described. The vacuum condition can include an intake manifold vacuum condition. For example, an intake manifold vacuum condition can exist during an engine idle condition, where the manifold pressure is lower than atmospheric pressure by a threshold amount. This vacuum in the intake system 23 can draw fuel vapor from the canister into the intake manifold 116 via the conduit 150 and the conduit 151, as represented by dashed arrows 167a, 103a, 103c, and 103d. In addition, at least a portion of the fuel vapor can flow from the conduit 150 into the ejector 140 via the port 144 via dashed arrow 103e. After entering the ejector via the port 144, the fuel vapor can flow through the nozzle 191 toward the port 142. In particular, the intake manifold vacuum causes the fuel vapor to flow through the bore 192. Because the diameter of the region within the nozzle increases in a direction from the port 144 toward the port 142, the fuel vapor diffuses as it flows through the nozzle in this direction, which raises the pressure of the fuel vapor. After passing through the nozzle, the fuel vapor exits the ejector 140 via the first port 142 and flows to the intake tract 118 and then to the intake manifold 116 via the conduit 148, as represented by dashed arrow 103f.

[0047] Operation of the ejector 140 within the fuel vapor purge system 171 during a boost condition will next be described. The boost condition can include a condition during which a mechanical compressor (e.g., 126) and / or an electric supercharger (e.g., 155) is in operation. For example, the boost condition can include one or more of a high engine load condition and a super-atmospheric pressure intake condition in which the intake manifold pressure is greater than atmospheric pressure by a threshold amount.

[0048] Fresh air enters intake passage 118 at air cleaner 174. During a boost condition, compressor 126 and / or electric supercharger 155 pressurizes the air in intake passage 118 such that the intake manifold pressure is positive. During operation of compressor 126, the pressure in intake passage 118 upstream of compressor 126 is lower than the intake manifold pressure, and this pressure differential causes fluid to flow from intake conduit 118 through conduit 148 and into injector 140 via injector inlet 142. In some examples, this fluid can include a mixture of air and fuel. After the fluid flows into the injector via port 142, it flows through converging orifice 192 in nozzle 191 in a direction from port 142 toward outlet 146. Because the diameter of the nozzle decreases along this flow direction, a low pressure region is created in the area of orifice 192 adjacent to suction port 144. The pressure in this low pressure region can be lower than the pressure in conduit 150. This pressure differential, when present, provides a vacuum to conduit 150 to draw fuel vapor from canister 104, as indicated by dashed arrows 105, 105a, 167a, and 105b. This pressure differential can further cause fuel vapor to flow from the fuel vapor canister through CPV1 (where the CPV is commanded to open) and into port 144 of injector 140. Upon entering the injector, the fuel vapor can be drawn from the injector via outlet port 146 with the fluid from the intake manifold, and drawn into intake conduit 118 at a location upstream of compressor 126, as indicated by dashed arrows 105c and 105d. Operation of compressor 126 then draws the fluid and fuel vapor from injector 140 into intake passage 118 and through compressor 126. After being compressed by compressor 126, the fluid and fuel vapor flow through charge air cooler 156 for delivery to intake manifold 116 via throttle 114. In examples where the electric supercharger is in use, the fluid can travel through compressor 126 and electric supercharger 155, where electric supercharger bypass valve 161 can be closed. However, in other examples where the electric supercharger is not in use, the fluid can travel through compressor 126 to charge air cooler via open electric supercharger bypass valve 161 for delivery to intake manifold 161. It can be appreciated that the above-described operation of injector 140 during a boost condition is related to an engine running condition, where the vehicle is in operation and the engine is burning air and fuel. However, there can be other opportunities to operate the vehicle system in a boost condition with the engine off. Such examples will be described in detail below.

[0049] The vehicle system 100 can further include a control system 160. The control system 160 is shown receiving information from a plurality of sensors 162 (multiple examples of which are described herein) and sending control signals to a plurality of actuators 164 (multiple examples of which are described herein). As one example, the sensors 162 can include the exhaust sensor 125 (located in the exhaust manifold 120) and various temperature and / or pressure sensors arranged in the intake system 23. For example, a pressure or airflow sensor 115 in the intake conduit 118 downstream of the throttle 114, a pressure or airflow sensor 117 in the intake conduit 118 between the compressor 126 and the throttle 114, and a pressure or airflow sensor 119 in the intake conduit 118 upstream of the compressor 126. In some examples, the pressure sensor 119 can include a dedicated barometric pressure sensor. Other sensors, such as additional pressure, temperature, air-fuel ratio, and composition sensors, can be coupled to various locations in the vehicle system 100. As another example, the actuators 164 can include the fuel injectors 132, the throttle 114, the compressor 126, the fuel pump of the pump system 130, and the like. The control system 160 can include an electronic controller 166. The controller can receive input data from the various sensors, process the input data, and in response to the processed input data, trigger actuators based on instructions or code programmed in the input data corresponding to one or more routines.

[0050] In some examples, the controller can be placed in a power-reduced mode or sleep mode, in which the controller only maintains basic functionality and operates with lower battery consumption as compared to in a corresponding wake mode. For example, the controller can be placed in a sleep mode after a vehicle-off event in order to perform a diagnostic routine for a duration of time after the vehicle-off event. The controller can have a wake-up input that allows the controller to return to the wake mode based on input received from one or more sensors. In some examples, the controller can schedule a wake-up time, which can include setting a timer, and when the timer time elapses, the controller can wake up from the sleep mode.

[0051] Diagnosis tests can be periodically performed on the evaporative emission control system 154 and the fuel system 106 to indicate the presence or absence of undesirable evaporative emissions. In one example, during a natural intake condition (e.g., intake manifold vacuum condition) in which the engine 112 is operating to combust air and fuel, the CVV 172 can be commanded to close and the CPV1 158 can be commanded to open. Additionally, the second CPV (CPV2) 165 can be commanded to close. By commanding the CVV 172, CPV2 165 to close and the CPV1 158 to open during a natural intake condition in which the engine is operating, the evaporative emission control system 154 and the fuel system 106 can be evacuated (as indicated via dashed arrows 103a, 167a, 167g, 167h, 103b, 103c, 103d, 167e, 167f) to ascertain the presence or absence of undesirable evaporative emissions by monitoring the pressure in the fuel system and the evaporative emission control system. Thus, it can be appreciated that the conduit 163a and the conduit 163b can be evacuated, but air can not flow through the CPV2 when the CPV2 is closed. The pressure in the fuel system and the evaporative emission control system can be monitored, for example, via the pressure sensor 107. In some examples, the pressure sensor 107 can include a fuel tank pressure sensor (FTPT). If a threshold vacuum (e.g., a negative pressure threshold relative to atmospheric pressure) is reached during the evacuation of the evaporative emission control system 154 and the fuel system 106, it can be indicated that there is not a significant undesirable evaporative emission. Additionally, if the threshold vacuum is reached, it can be indicated that the first check valve (CV1) 153 is not stuck closed or substantially closed, as the pressure sensor 107 can not indicate a pressure change if the CV1 153 is stuck closed. However, in the case of the CV1 being stuck closed, it can not be possible to indicate whether the threshold vacuum is not reached because the CV1 is stuck closed, or because of a significant undesirable evaporative emission in the evaporative emission control system and / or the fuel system. As will be discussed in further detail below, the inventors have developed systems and methods herein to address these issues. Further, in the case that the threshold vacuum is reached, thus indicating that there is not a significant undesirable evaporative emission and that the CV1 is functioning as desired, the CPV1 158 can be commanded to close and the pressure in the fuel system and the evaporative emission system can be monitored. A pressure rise (e.g., a bleed) that is greater than a predetermined pressure rise threshold or a pressure rise rate (bleed rate) that is greater than a predetermined pressure rise rate threshold can indicate that there is a non-significant undesirable evaporative emission.

[0052] While the above examples focus on the engine being in operation with a naturally aspirated condition of combusting air and fuel, there can be other (naturally aspirated) opportunities for such diagnostic testing of the presence or absence of undesirable evaporative emissions in the fuel system and evaporative emissions system in situations where the engine is not combusting air and fuel. For example, as discussed above, the vehicle propulsion system 100 can include an HEV or PHEV. Such hybrid drive systems can have limited engine run time, as the vehicle can operate using only power derived from the on-board energy storage device 250 for extended periods of time. Thus, it can be desirable to test for undesirable evaporative emissions using intake manifold vacuum in situations where the engine is not combusting air and fuel. Rather, the engine can be spun (without combusting air and fuel) using power supplied via the energy storage device 250 to operate the motor (e.g., 220, see Figure 2 ) without fueling. By spinning the engine without fueling, a vacuum (e.g., a negative pressure relative to atmospheric pressure) can be formed in the intake manifold. However, because the engine is not in operation to combust air and fuel, different strategies can be utilized to test for the presence of undesirable evaporative emissions. More specifically, if the same strategy as described above were to be utilized, fuel vapor can be drawn from the fuel tank 128 through the canister 104a and through the CPV 158 to the engine intake. In this scenario, the fuel vapor can not be sufficiently adsorbed by the canister 104a, and it can not be necessary to transport the fuel vapor from the fuel tank to the engine intake when the engine is not in operation to combust air and fuel. In this example, increased undesirable evaporative emissions can result, as the fuel vapor can be transported to the engine intake and then to the engine exhaust without combustion.

[0053] Accordingly, to avoid these issues, in response to the intake manifold vacuum being greater than the threshold intake manifold vacuum as a result of the engine being spun in the forward or default direction without fuel via the motor (e.g., 220), CPV1 158 can be commanded to close, and CPV2 165 can be commanded to open. Further, CVV 172 can be commanded to close. In this way, the fuel system and the evaporative emissions system can be evacuated via the paths defined by dashed arrows 167a, 167b, 103a, 167c, 167d, 167e, 167f, 103c, 103d, and 165i. In other words, fuel tank vapors can be drawn from the fuel tank 128 through the buffer 104a, through the non-buffer region 104b, through the vent line 136, and through the conduits 163b and 163a and 150, after which they are drawn through the first check valve 153 on the way to the engine intake. By evacuating the evaporative emissions system and the fuel system in this way, fuel tank vapors can be drawn across the entirety of the fuel vapor canister 104 (e.g., the buffer and the non-buffer region) so that the fuel vapors can be adsorbed before being carried to the engine intake.

[0054] Similar to the method described above with respect to evacuating the fuel system and the evaporative emissions system using the natural intake condition when the engine is operating to combust air and fuel, the method described by spinning the engine without fuel can enable a determination of whether CV1 is functioning as needed, for example, based on whether a threshold vacuum is reached in the fuel system and the evaporative emissions system, and whether significant undesirable evaporative emissions are not present. If the threshold vacuum is not reached, then either significant undesirable evaporative emissions can be present, or CV1 can be stuck closed. Further, in the case that the threshold vacuum is reached, thus indicating that significant undesirable evaporative emissions are not present and that CV1 is functioning as needed, CPV2 165 can be commanded to close and the pressure in the fuel system and the evaporative emissions system can be monitored. As discussed, a pressure bleed greater than a predetermined pressure rise threshold or a pressure bleed rate greater than a predetermined pressure rise rate threshold can indicate that non-significant undesirable evaporative emissions are present.

[0055] Another example describes a diagnostic test for the presence or absence of undesirable evaporative emissions originating from the fuel system and / or the evaporative emissions system while the engine is operating in a boosted condition in which air and fuel are being combusted (e.g., intake manifold pressure is greater than atmospheric pressure by a predetermined threshold). In this example, CVV 172 can be commanded to close, and CPV 1158 can be commanded to open. In addition, CPV2 165 can be commanded to close. By commanding CVV 172 and CPV2 165 to close and CPV1 158 to open during a boosted condition in which the engine is operating to combust air and fuel, the evaporative emissions control system 154 and the fuel system 106 can be evacuated (as indicated via dashed arrows 167a, 105, 105a, 105b, 105c, 105d, 103e, 103f) in order to ascertain the presence or absence of undesirable evaporative emissions. As shown, it can be appreciated that in this example, fuel vapor from the fuel tank can additionally be evacuated (dashed arrow 167a). However, because the engine is operating to combust air and fuel, any fuel vapor that is not sufficiently adsorbed via the buffer region 104a of the canister 104 can be combusted in the engine. In this way, a diagnosis can be made without adding undesirable evaporative emissions.

[0056] In such examples, during evacuation of the fuel system and the evaporative emissions system, pressure in the fuel system and the evaporative emissions control system can be monitored via, for example, pressure sensor 107 as described above. If a threshold vacuum (e.g., a negative pressure threshold relative to atmospheric pressure) is reached during evacuation of the evaporative emissions control system 154 and the fuel system 106, it can be indicated that there is not a significant presence of undesirable evaporative emissions. In addition, if the threshold vacuum is reached, it can be indicated that the second check valve (CV2) 170 is not stuck closed or substantially closed, as the pressure sensor 107 can not indicate a pressure change if CV2 170 is stuck closed. However, similar to that described above for the diagnostic test performed on the evaporative emissions control system 154 and the fuel system 106 in a natural intake condition, the diagnostic test performed during a boosted condition in which the threshold vacuum is not reached can not be able to distinguish whether the threshold vacuum is not achieved because CV2 is stuck closed or because there is a significant presence of undesirable evaporative emissions. Accordingly, the inventors have developed systems and methods herein to address these issues, which will be discussed in detail below.

[0057] While the above examples focus on the boosted condition where the engine is operating to combust air and fuel, there can be other opportunities for such diagnostic testing for the presence or absence of undesirable evaporative emissions in the fuel system and evaporative emissions system where the engine is not combusting air and fuel. For example, as discussed above, because the vehicle system can include an HEV or PHEV, where such a powertrain can have limited engine run time, there can be a need to test for the presence or absence of undesirable evaporative emissions at a condition of positive pressure in the intake manifold where the engine is not in operation. One such example includes supplying air to the intake manifold at positive pressure (relative to atmospheric pressure) via an electric supercharger 155 operated by power supplied from the energy storage device 250. By operating the electric supercharger 155 when the engine is off, the positive pressure in the intake manifold can in turn cause a negative pressure (relative to atmospheric pressure) to be delivered to the fuel system and evaporative emissions system via the injector system 141 as discussed above. However, similar to that discussed above for testing for undesirable evaporative emissions by spinning the engine without fueling, if a vacuum (negative pressure relative to atmospheric pressure) is delivered to the fuel system and evaporative emissions system with the CPV1 158 open and the CVV 172 closed, fuel tank vapors can be drawn from the fuel tank through the buffer 104a of the canister 104 and to the engine air intake without being adequately adsorbed by the canister. As noted, such a routine can result in increased undesirable evaporative emissions because the fuel vapors can be carried through the engine and to the engine exhaust (and to the atmosphere) without being combusted by the engine.

[0058] Accordingly, to avoid these problems, in response to activating the electric supercharger 155 to induce positive pressure in the air intake of the engine 112, the CPV1 158 can be commanded closed, the CPV2 165 can be commanded open, and the CVV 172 can be commanded closed. In this way, the fuel system and evaporative emissions system can be evacuated via the paths defined by the dashed arrows 167a, 167b, 103a, 167i, 167c, 167d, 167e, 167f, 103c, 103e, 105c, 105d, 103f) 105, 105a, 105b, 105c, 105d, 103e, 103f). In other words, fuel tank vapors can be drawn from the fuel tank 128 through the buffer 104a, through the non-buffer region 104b, through the breather line 136, and through the conduits 163b and 163a and 150, after which they are drawn through the second check valve 170 on the way to the engine air intake.

[0059] Similar to the methods described above with respect to evacuating the fuel system and evaporative emission system under boosted conditions when the engine is operating to combust air and fuel, the methods described by operating the electric supercharger when the engine is off (e.g., not combusting air and fuel and not spinning without fueling) can enable determining whether CV2 170 is functioning as desired and whether significant undesirable evaporative emissions are not present, e.g., whether a threshold vacuum is reached. If the threshold vacuum is not reached, then there can be significant undesirable evaporative emissions, or CV2 can be stuck closed. Further, in the case that the threshold vacuum is reached, thus indicating that significant undesirable evaporative emissions are not present and that CV2 is functioning as desired, the CPV2 165 can be commanded closed and the pressure in the fuel system and evaporative emission system can be monitored. As discussed, a pressure bleed greater than a predetermined pressure rise threshold or a pressure bleed rate greater than a predetermined pressure rise rate threshold can indicate that non-significant undesirable evaporative emissions are present.

[0060] As discussed above, in the case that the intake manifold vacuum alone is used to test for undesirable evaporative emissions, and / or in the case that the positive pressure in the intake system alone is used to test for undesirable evaporative emissions, interpreting the diagnostic results when the threshold vacuum is not reached in the fuel system and evaporative emission system can be challenging. In particular, as noted above, in the case that the threshold vacuum is not reached during evacuation of the fuel system and evaporative emission system via the intake manifold vacuum, it can not be clear whether CV1 is stuck closed or whether undesirable evaporative emissions are present in the fuel system and / or evaporative emission system. Similarly, in the case that the threshold vacuum is not reached during evacuation of the fuel system and evaporative emission system using the positive pressure in the intake system, it can not be clear whether CV2 is stuck closed or whether undesirable evaporative emissions are present in the fuel system and / or evaporative emission system.

[0061] Accordingly, to finally conclude whether the predetermined threshold value cannot be achieved during venting of the evaporative emission control system 154 and the fuel system 106 (under positive pressure conditions in the intake system or negative pressure conditions in the intake manifold) is because of a stuck closed CV1 or CV2 valve, or because of significant undesirable evaporative emissions, diagnostic testing under positive pressure conditions (e.g., boost) and negative pressure conditions (e.g., natural intake) can be utilized. For example, and discussed in greater detail below, diagnostic testing can first be performed under positive pressure conditions, and subsequently under natural intake conditions, or vice versa. By performing diagnostic testing under positive intake pressure conditions and under negative intake pressure conditions, the functionality of the CV1 153 and CV2 170 can finally be indicated, along with the presence or absence of undesirable evaporative emissions. Moreover, in response to an indication that the CV1 153 or CV2 170 is stuck closed, the purge operation can be updated such that the purge operation is performed only via a flow path that includes a check valve that is not stuck closed. Such examples are discussed in greater detail below with respect to Figures 3 to 7 and Figure 9 The illustrated method discusses such examples in detail.

[0062] Figure 2 An example vehicle propulsion system 200 is illustrated. It can be appreciated that the vehicle propulsion system 200 can include the same vehicle propulsion system as the vehicle propulsion system 100 illustrated. Figure 1 The vehicle propulsion system 200 includes a fuel burning engine 112 and a motor 220. As a non-limiting example, the engine 112 includes an internal combustion engine and the motor 220 includes an electric motor. The motor 220 can be configured to utilize or consume a different energy source than the engine 112. For example, the engine 112 can consume a liquid fuel (e.g., gasoline) to produce an engine output, while the motor 220 can consume electrical energy to produce a motor output. Accordingly, a vehicle having the propulsion system 200 can be referred to as a hybrid electric vehicle (HEV).

[0063] The vehicle propulsion system 200 can utilize a variety of different operating modes depending on the operating conditions encountered by the vehicle propulsion system. Some of these modes can enable the engine 112 to be maintained in an off state (i.e., set to an inactive state) in which fuel combustion at the engine is interrupted. For example, under selected operating conditions, when the engine 112 is inactive, the motor 220 can propel the vehicle via the drive wheels 230, as indicated by arrow 222.

[0064] During other operating conditions, the engine 112 can be set to an inactive state (as described above) while the motor 220 can be operated to charge the energy storage device 250. For example, the motor 220 can receive wheel torque from the drive wheels 230, as indicated by arrow 222, where the motor can convert the vehicle's kinetic energy into electrical energy for storage at the energy storage device 250, as indicated by arrow 224. This operation can be referred to as regenerative braking of the vehicle. Thus, in some examples, the motor 220 can provide a generator function. However, in other examples, a generator 260 can alternatively receive wheel torque from the drive wheels 230, where the generator can convert the vehicle's kinetic energy into electrical energy for storage at the energy storage device 250, as indicated by arrow 262.

[0065] During other operating conditions, the engine 112 can be operated by combusting fuel received from the fuel system 106, as indicated by arrow 242. For example, when the motor 220 is inactive, the engine 112 can be operated to propel the vehicle via the drive wheels 230, as indicated by arrow 212. During other operating conditions, the engine 112 and the motor 220 can each be operated to propel the vehicle via the drive wheels 230, as indicated by arrows 212 and 222, respectively. The configuration of both the engine and the motor selectively propelling the vehicle can be referred to as a parallel vehicle propulsion system. It should be noted that, in some examples, the motor 220 can propel the vehicle via a first set of drive wheels and the engine 112 can propel the vehicle via a second set of drive wheels.

[0066] In other examples, the vehicle propulsion system 200 can be configured as a series vehicle propulsion system, where the engine does not directly propel the drive wheels. Rather, the engine 112 can be operated to power the motor 220, which in turn can propel the vehicle via the drive wheels 230, as indicated by arrow 222. For example, during selected operating conditions, the engine 112 can drive the generator 260, as indicated by arrow 216, which in turn can supply electrical energy to one or more of the motor 220, as indicated by arrow 214, or the energy storage device 250, as indicated by arrow 262. As another example, the engine 112 can be operated to drive the motor 220, which in turn can provide a generator function to convert the engine output into electrical energy, where the electrical energy can be stored at the energy storage device 250 for subsequent use by the motor.

[0067] The fuel system 106 can include one or more fuel storage tanks 128 for storing fuel on the vehicle. For example, the fuel tank 128 can store one or more liquid fuels, including but not limited to gasoline, diesel, and alcohol fuels. In some examples, fuel can be stored on the vehicle as a mixture of two or more different fuels. For example, the fuel tank 128 can be configured to store a mixture of gasoline and ethanol (e.g., E10, E85, etc.) or a mixture of gasoline and methanol (e.g., M10, M85, etc.), where these fuels or fuel mixtures can be delivered to the engine 112 as indicated by arrow 242. Other suitable fuels or fuel mixtures can be supplied to the engine 112, where the fuels or fuel mixtures can be combusted at the engine to produce an engine output. The engine output can be used to propel the vehicle as indicated by arrow 212 or to recharge the energy storage device 250 via the motor 220 or generator 260.

[0068] In some examples, the energy storage device 250 can be configured to store electrical energy, which can be supplied to other electrical loads (in addition to the motor) residing on the vehicle, including cabin heating and air conditioning, generator starting, headlamps, cabin audio and video systems, etc. As a non-limiting example, the energy storage device 250 can include one or more batteries and / or capacitors.

[0069] The control system 160 can be in communication with one or more of the engine 112, the motor 220, the fuel system 106, the energy storage device 250, and the generator 260. The control system 160 can receive sensory feedback information from one or more of the engine 112, the motor 220, the fuel system 106, the energy storage device 250, and the generator 260. Additionally, the control system 160 can send control signals to one or more of the engine 112, the motor 220, the fuel system 106, the energy storage device 250, and the generator 260 in response to this sensory feedback. The control system 160 can receive an indication of an operator-requested output of the vehicle propulsion system from the vehicle operator 202. For example, the control system 160 can receive sensory feedback from a pedal position sensor 294 in communication with a pedal 292. The pedal 292 can illustratively be a brake pedal and / or an accelerator pedal. Further, in some examples, the control system 160 can be in communication with a remote engine start receiver 295 (or transceiver) that receives a wireless signal 206 from a key fob 204 having a remote start button 205. In other examples (not shown), a remote engine start can be initiated via a cellular phone or smart phone based system in which a user's cellular phone sends data to a server and the server communicates with the vehicle to start the engine.

[0070] The energy storage device 250 can periodically receive electrical energy from a power source 280 (e.g., not part of the vehicle) residing outside of the vehicle, as indicated by arrow 284. As a non-limiting example, the vehicle propulsion system 200 can be configured as a plug-in hybrid electric vehicle (PHEV), in which electrical energy can be supplied from the power source 280 to the energy storage device 250 via an electrical energy transfer cable 282. During operation to recharge the energy storage device 250 from the power source 280, the electrical energy transfer cable 282 can electrically couple the energy storage device 250 and the power source 280. The electrical energy transfer cable 282 can be disconnected between the power source 280 and the energy storage device 250 when the vehicle propulsion system is operated to propel the vehicle. The control system 160 can identify and / or control the amount of electrical energy stored at the energy storage device, which can be referred to as the state of charge (SOC).

[0071] In other examples, the electrical energy transfer cable 282 can be omitted, in which electrical energy can be received wirelessly at the energy storage device 250 from the power source 280. For example, the energy storage device 250 can receive electrical energy from the power source 280 via one or more of electromagnetic induction, radio waves, and electromagnetic resonance. Thus, it can be appreciated that any suitable method can be used to recharge the energy storage device 250 from a power source that does not form part of the vehicle. In this manner, the motor 220 can propel the vehicle by utilizing an energy source other than fuel utilized by the engine 112.

[0072] The fuel system 106 can periodically receive fuel from a fuel source residing outside of the vehicle. As a non-limiting example, the vehicle propulsion system 200 can be refueled by receiving fuel from a fuel dispensing device 270, as indicated by arrow 272. In some examples, the fuel tank 128 can be configured to store fuel received from the fuel dispensing device 270 until it is supplied to the engine 112 for combustion. In some examples, the control system 160 can receive an indication of a level of fuel stored at the fuel tank 128 via a fuel level sensor. The level of fuel stored at the fuel tank 128 (e.g., as identified by the fuel level sensor) can be communicated to a vehicle driver, for example, via a fuel gauge or indicator in a vehicle dashboard 296.

[0073] The vehicle propulsion system 200 can also include an ambient temperature / humidity sensor 298, and roll stability control sensors, such as lateral and / or longitudinal and / or yaw rate sensors 299. The vehicle dashboard 296 can include indicator lights and / or a text-based display in which messages are displayed to the driver. The vehicle dashboard 296 can also include various input portions for receiving driver input, such as buttons, touchscreens, voice input / recognition, etc. For example, the vehicle dashboard 296 can include a refuel button 297 that can be manually actuated or pressed by the vehicle driver to initiate refueling. For example, in response to the vehicle driver actuating the refuel button 297, the fuel tank in the vehicle can be depressurized so that refueling can be performed.

[0074] In some examples, the vehicle propulsion system 200 can include one or more on-board cameras 235. For example, the on-board cameras 235 can communicate photographic and / or video images to the control system 160. In some examples, for example, the on-board cameras can be used to record images within a predetermined radius of the vehicle.

[0075] The control system 160 can be communicatively coupled to other vehicles or infrastructure using appropriate communication techniques as known in the art. For example, the control system 160 can be coupled to other vehicles or infrastructure via a wireless network 231, which can include Wi-Fi, Bluetooth, a cellular service, a wireless data transfer protocol, etc. The control system 160 can broadcast (and receive) information about vehicle data, vehicle diagnostics, traffic conditions, vehicle location information, vehicle operating procedures, etc. via vehicle-to-vehicle (V2V), vehicle-to-infrastructure-to-vehicle (V2I2V), and / or vehicle-to-infrastructure (V2I or V2X) techniques. Communication between vehicles and exchanged information can be directly between vehicles, or can be multi-hop. In some examples, long-range communication (e.g., WiMax) can be used instead of or in conjunction with V2V or V2I2V to extend coverage several miles. In other examples, the vehicle control system 160 can be communicatively coupled to other vehicles or infrastructure via the wireless network 231 and the Internet (e.g., the cloud), as is well known in the art.

[0076] The vehicle system 200 can also include an on-board navigation system 232 (e.g., a global positioning system) with which the vehicle driver can interact. The navigation system 232 can include one or more position sensors for assisting in estimating vehicle speed, vehicle height, vehicle positioning / location, etc. This information can be used to infer engine operating parameters, such as local atmospheric pressure. As discussed above, the control system 160 can be further configured to receive information via the Internet or other communication network. Information received from the GPS can be cross-referenced with information available via the Internet to determine local weather conditions, local vehicle regulations, etc.

[0077] Accordingly, as discussed herein, a system for a vehicle can include an engine including an air intake, a motor configured to spin the engine without fuel, a fuel system including a fuel tank fluidly coupled to an evaporative emissions system including a fuel vapor canister, a canister vent valve in a vent line coupling the fuel vapor canister to atmosphere, a first canister purge valve in a purge line originating from the fuel vapor canister, a second canister purge valve selectively fluidly coupled to the purge line via a first conduit and selectively fluidly coupled to the vent line via a second conduit, a first check valve in a conduit upstream of an air intake of the engine and downstream of the first and second canister purge valves, a second check valve in the purge line downstream of the conduit downstream of the first and second canister purge valves and upstream of the air intake of the engine, an eductor system downstream of the second check valve, an electric compressor in an air intake upstream of an air intake throttle and configured to supply air to the engine, and a fuel tank pressure sensor between the fuel tank and the fuel vapor canister. The system can include a controller storing instructions in a non-transitory memory. The instructions, when executed, can in a first condition, evacuate the fuel system and evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the first check valve by spinning the engine without fuel via the motor to create a vacuum in the air intake of the engine to evacuate the fuel system and evaporative emissions system. In a second condition, the controller can evacuate the fuel system and evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and evaporative emissions system via the second check valve via the eductor system with the electric compressor activated. The controller can further indicate a presence or absence of significant undesirable evaporative emissions depending on whether a threshold vacuum is reached during evacuation of the fuel system and the evaporative emissions system in the first and second conditions, and whether the first and second check valves are functioning as needed, where the threshold vacuum is indicated via the fuel tank pressure sensor.The controller can be further configured to store additional instructions to indicate, in response to reaching the threshold vacuum in both the first condition and the second condition, that both the first check valve and the second check valve are functioning as desired and that there is no significant undesirable evaporative emissions. The controller can be further configured to store additional instructions to indicate, in response to reaching the threshold vacuum in the second condition but not the first condition, that the first check valve is stuck closed but the second check valve is functioning as desired and that there is no significant undesirable evaporative emissions. The controller can be further configured to store additional instructions to indicate, in response to reaching the threshold vacuum in the first condition but not the second condition, that the second check valve is stuck closed but the first check valve is functioning as desired and that there is no significant undesirable evaporative emissions. Additionally, the controller can be further configured to store additional instructions to indicate, in response to not reaching the threshold vacuum during either the first condition or the second condition, that there is significant undesirable evaporative emissions.

[0078] In one example of this system, the controller can store additional instructions to indicate, in response to reaching the threshold vacuum in both the first condition and the second condition, that both the first check valve and the second check valve are functioning as desired and that there is no significant undesirable evaporative emissions. The controller can store additional instructions to indicate, in response to reaching the threshold vacuum in the second condition but not the first condition, that the first check valve is stuck closed but the second check valve is functioning as desired and that there is no significant undesirable evaporative emissions. The controller can store additional instructions to indicate, in response to reaching the threshold vacuum in the first condition but not the second condition, that the second check valve is stuck closed but the first check valve is functioning as desired and that there is no significant undesirable evaporative emissions. Additionally, the controller can store additional instructions to indicate, in response to not reaching the threshold vacuum during either the first condition or the second condition, that there is significant undesirable evaporative emissions.

[0079] In some examples of this system, the controller can store additional instructions to, in response to reaching the threshold vacuum in either or both of the first condition and / or the second condition, seal the fuel system and the evaporative emissions system by commanding the second canister purge valve to close and commanding or maintaining the canister vent valve and the first canister purge valve to close. The controller can store additional instructions to monitor pressure in the fuel system and evaporative emissions system via the fuel tank pressure sensor; and in response to pressure in the fuel system and the evaporative emissions system remaining below a pressure rise threshold for a predetermined duration, or in response to a rate of pressure rise in the fuel system and the evaporative emissions system remaining below a pressure rise rate threshold, indicate that there is no significant undesirable evaporative emissions.

[0080] Turning to Figure 3A flowchart of a high-level example method 300 for performing an evaporative emission test diagnostic procedure on an evaporative emission control system (e.g., 154) and a fuel system (e.g., 106) is shown. More specifically, method 300 can be used to perform an evaporative emission test diagnostic procedure by operating or activating (e.g., turning on) an electric supercharger (e.g., 155) when the vehicle's engine is not in operation. By activating the electric supercharger, the pressure in the engine's intake port can become positive relative to atmospheric pressure, which can result in a negative pressure relative to atmospheric pressure being transmitted to the fuel system and the evaporative emission system. The positive pressure in the intake port is then delivered through the injector system (e.g., 141), which can reduce the pressure in the fuel system and the evaporative emission system via the Venturi effect. In this way, the evaporative emission test procedure can be performed with the engine off, which may be desirable in the case of HEVs or PHEVs, where such vehicles may have limited engine operating time.

[0081] It is understood that in some examples, an evaporative emission test procedure can be performed using an electric supercharger if the vehicle is not in operation, or if the vehicle is in operation but the engine is off (e.g., only the vehicle is electrically operated). By performing the evaporative emission test via activating the electric supercharger, an indication can be given that a threshold vacuum is reached during the evaporative emission test diagnostics, ultimately indicating the absence of significant unwanted evaporative emissions and that the second check valve (CV2) (e.g., 170) is not stuck closed. In response to reaching the threshold, the fuel system and the evaporative emission system can be sealed, and pressure relief can be monitored to indicate the presence or absence of non-significant unwanted evaporative emissions. Furthermore, in response to an indication that the threshold vacuum is not reached during the evaporative emission test diagnostics, a significant unwanted emission can be indicated, or that CV2 is stuck closed. Regardless of whether the threshold vacuum is reached, the results of the evaporative emission test diagnostics can be stored at the controller, as discussed in further detail below.

[0082] Please refer to the descriptions in this article and Figures 1 to 2 The system described herein is method 300, but it should be understood that similar methods can be applied to other systems without departing from the scope of this disclosure. Method 300 can be executed by a controller, such as... Figure 1 The controller 166 is configured to store executable instructions in non-transitory memory at the controller. Instructions for performing method 300 and the remaining methods included herein can be generated by the controller based on instructions stored in the controller's memory and in conjunction with those from sensors in the engine system (such as those referenced above). Figures 1 to 2The controller can employ fuel system and evaporative emission system actuators, such as a first canister purge valve (CPV1) (e.g., 158), a second canister purge valve (CPV2) (e.g., 165), a canister vent valve (CVV) (e.g., 172), an electric supercharger (e.g., 155), etc., in accordance with the methods below.

[0083] Method 300 begins at 305 and can include estimating and / or measuring vehicle conditions. Conditions can be estimated, measured, and / or inferred, and can include one or more vehicle conditions such as vehicle speed, vehicle location, etc., various engine conditions such as engine state, engine load, engine speed, A / F ratio, manifold air pressure, etc., various fuel system conditions such as fuel level, fuel type, fuel temperature, etc., various evaporative emission system conditions such as fuel vapor canister load, fuel tank pressure, etc., and various environmental conditions such as ambient temperature, humidity, barometric pressure, etc.

[0084] Continuing at 310, the method 300 can include indicating whether conditions are met for an engine off boost evaporative emissions test. Conditions met at 310 can include a threshold duration of time elapsed since a previous engine off boost evaporative emissions test or other evaporative emissions test of the fuel system and / or evaporative emissions system in which positive pressure in the engine intake is used to conduct the test. In another example, conditions met can include a threshold state of charge (SOC) of an on-board energy storage device (e.g., battery, capacitor, super capacitor, etc.). The threshold SOC can include a threshold SOC that enables the use of the electric supercharger (e.g., 155) to evacuate the fuel system and evaporative emissions system without adversely affecting other vehicle operating parameters that can utilize energy provided via the on-board energy storage device. Conditions met at 310 can additionally or alternatively include an indication of a threshold amount of time since the engine was last operated. In some examples, the threshold amount of time can include an amount of time since the engine to any heat soak of the fuel system and / or evaporative emissions system can not adversely affect the engine off boost evaporative emissions test. As discussed above, the engine off boost evaporative emissions test can in some examples be conducted with the vehicle in operation but the engine off (e.g., electric only operating mode) or can be conducted with the engine off and the vehicle not in operation (e.g., key-off). In examples in which the engine off boost evaporative emissions test is conducted with the vehicle not in operation, the method can include waking up the controller at a predetermined time after a key-off event in order to conduct the test. In one example, the predetermined time can vary with a last engine start event, a duration of the last engine start event, environmental conditions such as temperature and / or humidity, etc. Conditions met at 310 can additionally or alternatively include an indication that a purge event is not in progress. Additionally, in some examples, conditions met at 310 can include an indication that there has not been undesirable evaporative emissions in the fuel system and / or evaporative emissions system previously, and an indication that CV2 (e.g., 170) has not been stuck closed previously.

[0085] If at 310 it is indicated that conditions for conducting the test are not met, the method 300 can proceed to 315. At 315, the method 300 can include maintaining the current vehicle operating state. For example, at 315, the method 300 can include maintaining CPV1 in its current configuration, maintaining CPV2 in its current configuration, and maintaining CVV in its current configuration. Additionally, other engine system actuators such as the throttle, fuel injectors, etc. can be maintained in their current state. The method 300 can then end.

[0086] Returning to 310, in response to indicating that conditions for performing an engine off boost evaporative emissions test are met, method 300 can proceed to 320. At 320, method 300 can include activating or actuating an open electric supercharger (e.g., 155). More specifically, as discussed above, the controller can send a signal to the electric supercharger actuator 155b to actuate the open electric supercharger. By actuating the open electric supercharger, a positive pressure relative to atmospheric pressure can be created in the engine air intake (e.g., 23). In one example, the open electric supercharger can be actuated at its full capacity to rapidly increase the pressure in the engine air intake. However, in other examples, the open electric supercharger can be actuated at any capacity that is predetermined to provide sufficient positive pressure in the engine air intake to evacuate the fuel system and evaporative emissions system within a predetermined amount of time. In some examples, the actuation of the electric supercharger can be a function of the SOC of the on-board energy storage device.

[0087] With the electric supercharger activated at 320, method 300 can proceed to 325. At 325, method 300 can include commanding the closed (actuating closed) CVV, and commanding the closed (actuating closed) CPV1. Proceeding to 330, method 300 can include commanding the open (actuating open) CPV2. By commanding the closed CVV and CPV1, while commanding the open CPV2, the vacuum from the injector system (e.g., 140) can be applied to the evaporative emissions system (e.g., 154) and the fuel system (e.g., 106) under a boosted condition. More specifically, by commanding the closed CVV at step 325, the evaporative emissions system and the fuel system can be sealed from atmospheric air. By commanding the open CPV2 at 330, the vacuum from the injectors can be applied to the sealed evaporative emissions system and fuel system. It can be appreciated that if CPV1 was commanded open instead of CPV2, the vacuum from the injector system can draw fuel vapor from the fuel tank through the buffer (e.g., 104a) of the canister (e.g., 104) without carrying the fuel vapor through the non-buffer region (e.g., 104b), which can result in an undesirable increase in emissions as the fuel vapor can not be combusted in the engine as the engine is off. Rather, by commanding the open CPV2 while CPV1 is closed, the vacuum from the injector system can draw the fuel tank vapor through the entire canister on its way to the engine air intake. In this way, the fuel vapor can be effectively adsorbed by the canister, which can prevent or reduce the release of undesirable emissions into the atmosphere.

[0088] At 335, the method 300 can include monitoring for vacuum buildup in the evaporative emission system and the fuel system. For example, monitoring for vacuum buildup (e.g., a negative pressure relative to atmospheric pressure) can include monitoring pressure via a pressure sensor (e.g., 107) located in the fuel system and / or the evaporative emission system. In some examples, monitoring for vacuum buildup at 335 can be performed for a predetermined duration of time.

[0089] Continuing at 340, the method 300 can include indicating whether vacuum buildup as monitored by the pressure sensor during evacuation of the evaporative emission system and the fuel system is greater than a predetermined threshold vacuum (e.g., more negative than the predetermined threshold vacuum). In some examples, the predetermined threshold vacuum can vary with atmospheric pressure. For example, the predetermined threshold vacuum can include a vacuum level that decreases in response to decreasing atmospheric pressure, and a vacuum level that increases in response to increasing atmospheric pressure. The predetermined threshold vacuum can further be based on a predetermined diameter or area of an orifice through which undesirable evaporative emissions can escape from the fuel system and / or the evaporative emission system.

[0090] At 340, if it is indicated that vacuum buildup in the fuel system and the evaporative emission system has reached the predetermined threshold vacuum, the method 300 can proceed to 345. At 345, the method 300 can further include indicating that the CV2 (e.g., 170) is not stuck closed. If the CV2 is stuck closed, the pressure sensor (e.g., 107) would not record a change in pressure during evacuation of the fuel system and the evaporative emission system. In other words, the CV2 must be functioning as needed in response to reaching the predetermined threshold vacuum. Furthermore, at 345, it can be indicated that there is not significant undesirable evaporative emissions originating from the fuel system and / or the evaporative emission system. For example, the method 300 can include indicating that there is not significant undesirable evaporative emissions originating from an orifice of a size of the predetermined diameter or area discussed above at 340, where the predetermined diameter or area corresponds to significant undesirable evaporative emissions. In some examples, significant undesirable evaporative emissions can include a diameter of the orifice corresponding to 0.04” or greater.

[0091] Continuing at 350, the method 300 can include closing the CPV2 to isolate the fuel system and evaporative emission system from the atmosphere and the engine intake, and monitoring pressure bleed-off in the fuel system and evaporative emission system. Further, at 350, the method 300 can include actuating the closing (deactivation) of the electric supercharger. With the fuel system and evaporative emission system isolated from the atmosphere and the engine intake, the pressure in the fuel system and evaporative emission system can be monitored by a pressure sensor (e.g., 107). In some examples, the pressure can be monitored for a predetermined duration. If the pressure in the fuel system and evaporative emission system reaches a predetermined pressure rise threshold, or if the pressure bleed-off rate exceeds a predetermined pressure rise rate threshold, then a non-significant undesirable evaporative emission can be indicated. However, if the pressure does not reach the predetermined pressure rise threshold, or if the pressure bleed-off rate does not exceed the predetermined pressure rise rate threshold, then the absence of a non-significant undesirable evaporative emission can be indicated. Although step 345 includes indicating the absence of a significant undesirable evaporative emission, it will be appreciated that at step 350, indicating the presence or absence of a non-significant undesirable evaporative emission includes undesirable evaporative emissions (non-significant undesirable evaporative emissions) originating from an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. For example, at 350, the non-significant undesirable evaporative emission can be indicated as corresponding to an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. Thus, step 350 includes testing for the presence or absence of a non-significant undesirable evaporative emission by comparing a change in pressure in the fuel system or evaporative emission system after the fuel system and evaporative emission system is evacuated to a reference change in pressure.

[0092] Proceeding to step 355, the method 300 can include storing the results of the evaporative emission test diagnostic procedure at the controller. As will be discussed in further detail below, the results of the evaporative emission test diagnostic procedure conducted in accordance with the method 300 can be used in conjunction with the results of an evaporative emission test diagnostic procedure conducted with a negative pressure in the intake of the engine (see Figures 5 to 7 ) in some examples in order to ultimately determine the presence or absence of undesirable evaporative emissions, and the functionality of the CV2 (e.g., 170) and the first check valve (CV1) (e.g., 153).

[0093] At 355, the method 300 can include updating vehicle operating parameters in response to the results of the evaporative emission test diagnostic. For example, in response to an indication of the absence of a significant undesirable evaporative emission, but further in response to an indication of the presence of a non-significant undesirable evaporative emission, updating vehicle operating parameters can include adjusting an evaporative emission test schedule, and can further include illuminating a malfunction indicator light (MIL) on a vehicle dashboard alerting a vehicle driver that it is prudent to service the vehicle.

[0094] In some examples, in response to an absence of significant undesirable evaporative emissions and further in response to an indication of non-significant undesirable evaporative emissions, the vehicle operating conditions can be updated such that the evaporative emissions system can be configured with the CVV closed, the CPV1 closed, and the CPV2 open. With the evaporative emissions system so configured, fuel tank vapors can travel from the fuel tank, through the entire fuel vapor canister (e.g., both the buffer and non-buffer regions) on the way to the engine air intake. In such examples, the vehicle system can be further configured to operate in an electric mode of operation as much as possible during subsequent times of vehicle operation. In this way, fuel tank vapors can be carried through the entire canister and then can be carried to the engine air intake. However, with the engine off, any fuel tank vapors that are not adsorbed by the canister can be adsorbed via the AIS HC trap (e.g., 169) located in the air intake of the engine. In this way, even in the condition where there is an indication of non-significant undesirable evaporative emissions, undesirable evaporative emissions can be reduced. More specifically, if there is a small (e.g., non-significant) source of undesirable evaporative emissions, by carrying the fuel tank vapors through the entire fuel vapor canister on the way to the engine air intake via the open CPV2 (and closed CVV), it is more likely that the vapors can travel to the engine air intake as discussed, rather than being released to the atmosphere, because the flow resistance on the way to the engine air intake is less than through the small source.

[0095] Additionally, at 355, in response to an indication of an absence of significant undesirable evaporative emissions and further in response to an indication of an absence of non-significant undesirable evaporative emissions, the method 300 can include maintaining the CPV1 closed, maintaining the CPV2 closed, and commanding the CVV open. By maintaining the CPV1 and CPV2 closed, the fuel system and the evaporative emissions system can be sealed off from the engine air intake (and from the injectors). Further, by commanding the CVV open, fuel vapors generated in the fuel tank (e.g., run loss fuel vapors, refueling vapors, or vapors caused by diurnal temperature fluctuations) can be carried to the fuel vapor canister (e.g., 104) for storage before exiting to the atmosphere. The method 300 can then end.

[0096] Returning to 340, if the indication of vacuum buildup in the fuel system and the evaporative emissions system does not reach the predetermined threshold vacuum, the method 300 can proceed to 365. At 365, the method 300 can include indicating that the CV2 is stuck closed, or that there is significant undesirable evaporative emissions in the fuel system and the evaporative emissions system. In other words, because the CV2 is stuck closed, or because of significant undesirable evaporative emissions, the vacuum buildup can be prevented from reaching the predetermined vacuum threshold. Accordingly, at 365 no final determination can be indicated as to the source of the inability to reach the predetermined threshold vacuum. Rather, the method 300 can proceed to 370. At 370, the method 300 can include commanding the closing (actuating the closing) of the CPV2, and can include deactivating the electric supercharger. Proceeding to 355, the method 300 can include storing the results of the evaporative emissions test diagnosis at the controller, and can further include updating the vehicle operating conditions. Updating the vehicle operating conditions at 355 can include scheduling a test for undesirable evaporative emissions in a condition of negative pressure in the intake of the engine relative to atmospheric pressure, in order to determine whether the CV2 is stuck closed, or whether there are significant undesirable evaporative emissions, as will be discussed below with respect to Figures 5 to 8 The method 300 can then end.

[0097] Although Figure 3 The example is shown in which the electric supercharger is used to test for undesirable evaporative emissions, in other examples such a test can be performed while the engine is in operation combusting air and fuel. This example will be discussed below with respect to Figure 4 .

[0098] Turning to Figure 4 , another flowchart is shown of a high level example method 400 for performing an evaporative emissions test diagnostic procedure for an evaporative emissions control system (e.g., 154) and a fuel system (e.g., 106). More specifically, the method 400 can be used to perform an evaporative emissions test diagnostic procedure in response to an indication that conditions for an evaporative emissions test under a boosted condition are met, where the boosted condition includes an engine start condition (as opposed to Figure 3 , an engine running condition (as opposed to Figure 3(Engine not in operation). It is understood that engine start-up status includes the condition that the engine is operating to burn air and fuel. Performing this evaporative emissions test diagnostic procedure may involve coupling the fuel system and evaporative emissions system to the compressor inlet via orifices with inlet pressure reduced by the Venturi effect, thus enabling purging of the fuel system and evaporative emissions system under boost conditions. In this way, by performing the evaporative emissions test under boost conditions, an indication can be given that no unwanted evaporative emissions are present and the second check valve (CV2) (e.g., 170) is not stuck closed, in response to an indication that a threshold vacuum is reached during the evaporative emissions test diagnostic procedure. Furthermore, an indication that the threshold vacuum is not reached during the evaporative emissions test diagnostic procedure may indicate the presence of significant unwanted emissions or that CV2 is stuck closed. Regardless of whether the threshold vacuum is reached, the results of the evaporative emissions test diagnostic procedure can be stored at the controller, as discussed in further detail below.

[0099] Please refer to the descriptions in this article and Figures 1 to 2 The system described herein is method 400, but it should be understood that similar methods can be applied to other systems without departing from the scope of this disclosure. Method 400 can be executed by a controller, such as... Figure 1 The controller 166 is configured to store executable instructions in non-transitory memory at the controller. Instructions for performing method 400 and the remaining methods included herein can be generated by the controller based on instructions stored in the controller's memory and in conjunction with those from sensors in the engine system (such as those referenced above). Figures 1 to 2 The controller executes actions based on signals received by the described sensor. According to the method described below, the controller may employ fuel system and evaporative emission system actuators, such as a first filter canister flush valve (CPV1) (e.g., 158), a second filter canister flush valve (CPV2) (e.g., 165), a filter canister vent valve (CVV) (e.g., 172), etc.

[0100] Understandably, method 400 is basically similar to Figure 3 The method 300 shown here differs from the method 400 in that it is performed via boost provided by engine operation (and in some examples supplemented by electric boost). However, for clarity, the entirety of method 400 will be described below.

[0101] Method 400 begins at 405 and can include estimating and / or measuring vehicle operating conditions. Operating conditions can be estimated, measured, and / or inferred, and can include one or more vehicle conditions such as vehicle speed, vehicle location, etc., various engine conditions such as engine state, engine load, engine speed, A / F ratio, manifold air pressure, etc., various fuel system conditions such as fuel level, fuel type, fuel temperature, etc., various evaporative emission system conditions such as fuel vapor canister load, fuel tank pressure, etc., and various environmental conditions such as ambient temperature, humidity, barometric pressure, etc.

[0102] Continuing at 410, method 400 can include indicating whether conditions for an evaporative emission test under boost with the engine operating are satisfied. For example, conditions for an evaporative emission test under boost that are satisfied can include an indication that manifold air pressure (MAP) is greater than barometric pressure (BP) by a predetermined threshold amount when the engine is operating. In some examples, conditions that are satisfied at 410 can include that MAP is greater than BP by a predetermined threshold for a predetermined duration. In some examples, conditions that are satisfied at 410 can further include an indication that evaporative emission control system and fuel system have not been diagnosed for an evaporative emission test under boost conditions during the current drive cycle. In some examples, conditions that are satisfied at 410 can further include an indication that no evaporative emission test under boost has been performed for a predetermined duration. For example, consider a situation where an engine off boost evaporative emission test has just been performed immediately prior to activating (starting) the vehicle with engine operation. In this example, an engine on boost evaporative emission test can not be required because the state of the fuel system and evaporative emission system can not have changed since the previous test. Thus, in some examples, the predetermined duration for which an engine on boost evaporative emission test can not be performed in response to a recent engine off boost evaporative emission test can include 5 hours, 4 hours, 3 hours, 2 hours, 1 hour, less than 1 hour, etc. In some examples, conditions that are satisfied at 410 can further include an indication that a purge event is not in progress. Additionally, in some examples, conditions that are satisfied at 410 can include an indication that no undesirable evaporative emissions in the fuel system and / or evaporative emission system have occurred previously, and that CV2 (e.g., 170) has not been stuck closed previously.

[0103] If at 410 it is indicated that the condition of the evaporative emission test diagnostic procedure under boost with the engine in operation is not satisfied, the method 400 can proceed to 415. At 415, the method 400 can include maintaining the current vehicle operating state. For example, at 415, the method 400 can include maintaining CPV1 and CPV2 in their current configuration, and can further include maintaining CVV in its current configuration. In addition, other engine system actuators such as the throttle, fuel injectors, etc. can be maintained in their current state. The method 400 can then end.

[0104] Returning to 410, if it is indicated that the condition of the evaporative emission test diagnostic procedure under boost with the engine in operation is satisfied, the method 400 can proceed to 420. At 420, the method 400 can include commanding the CVV to close (actuating closed). Proceeding to 425, the method 400 can include commanding the CPV1 to open (actuating open). Although not explicitly shown, it will be appreciated that at step 425, the method 400 can further include commanding or maintaining the CPV2 closed. By commanding the CVV to close and commanding the CPV1 to open with the CPV2 closed, vacuum from the injectors (e.g., 140) can be applied to the evaporative emission system (e.g., 154) and the fuel system (e.g., 106) under boost conditions. More specifically, by commanding the CVV to close at step 420, the evaporative emission system and the fuel system can be sealed from atmospheric air. By commanding the CPV1 to open at 425, vacuum from the injectors can be applied to the sealed evaporative emission system and fuel system. Although opening the CPV1 to draw vacuum on the fuel system and evaporative emission system can transport fuel tank vapors through the buffer (e.g., 104a) without traveling through the entire fuel vapor canister, this action can be tolerable because the engine is in operation. Thus, and fuel vapors transported to the engine intake can be combusted in the engine.

[0105] Proceeding to 430, the method 400 can include monitoring vacuum buildup in the evaporative emission system and the fuel system. For example, monitoring vacuum buildup (e.g., negative pressure relative to atmospheric pressure) can include monitoring pressure via a pressure sensor (e.g., 107) located in the fuel system and / or the evaporative emission system. In some examples, monitoring vacuum buildup at 430 can be conducted for a predetermined duration of time.

[0106] Accordingly, at 435, the method 400 can include indicating whether a vacuum buildup as monitored by the pressure sensor during evacuation of the evaporative emission system and the fuel system is greater than a predetermined vacuum threshold. In some examples, the predetermined vacuum threshold can vary with atmospheric pressure. For example, the predetermined vacuum threshold can include a vacuum level that decreases in response to decreasing atmospheric pressure, and a vacuum level that increases in response to increasing atmospheric pressure. The predetermined vacuum threshold can further be based on a predetermined diameter or area of an orifice through which undesirable evaporative emissions can escape from the fuel system and / or the evaporative emission system.

[0107] At 435, if it is indicated that the vacuum buildup in the fuel system and the evaporative emission system has reached the predetermined vacuum threshold, the method 400 can proceed to 440. At 440, the method 400 can include indicating that the CV2 (e.g., 170) is not stuck closed. If the CV2 is stuck closed, the pressure sensor (e.g., 107) would not record a change in pressure during evacuation of the fuel system and the evaporative emission system. In other words, the CV2 must be functioning as needed in response to reaching the predetermined threshold vacuum. Further, at 440, it can be indicated that there is not a significant undesirable evaporative emission originating from the fuel system and / or the evaporative emission system. For example, the method 400 can include indicating that there is not a significant undesirable evaporative emission originating from an orifice of a size of a predetermined diameter or area discussed above at 435, where the predetermined diameter or area corresponds to a significant undesirable evaporative emission. In some examples, the significant undesirable evaporative emission can include a diameter of an orifice corresponding to 0.04” or greater.

[0108] At 445, the method 400 can include closing the CPV1 to isolate the fuel system and evaporative emission system from the atmosphere and the engine intake, and monitoring the pressure bleed down in the fuel system and evaporative emission system. Again, the pressure can be monitored by a pressure sensor (e.g., 107). In some examples, the pressure can be monitored for a predetermined duration. If the pressure in the fuel system and evaporative emission system reaches a predetermined pressure rise threshold, or if the pressure bleed down rate exceeds a predetermined pressure rise rate threshold, then a non-significant undesirable evaporative emission can be indicated. However, if the pressure does not reach the predetermined pressure rise threshold during the predetermined duration, or if the pressure bleed down rate does not exceed the predetermined pressure rise rate threshold, then the absence of a non-significant undesirable evaporative emission can be indicated. Although step 440 includes indicating the absence of a significant undesirable evaporative emission, it can be appreciated that at step 445, indicating the presence or absence of a non-significant undesirable evaporative emission includes undesirable evaporative emissions originating from an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. For example, at 445, the non-significant undesirable evaporative emission can be indicated as corresponding to an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. Thus, step 445 includes testing for the presence or absence of a non-significant undesirable evaporative emission by comparing a change in pressure in the fuel system or evaporative emission system after the fuel system and evaporative emission system is evacuated to a reference change in pressure.

[0109] At step 450, the method 400 can include storing the results of the evaporative emission test diagnostic procedure at the controller. As will be discussed in further detail below, the results of the evaporative emission test diagnostic procedure conducted in accordance with the method 400 can be used in combination with the results of an evaporative emission test diagnostic procedure conducted with a negative pressure in the intake of the engine (see Figures 5 to 7 ) in some examples in order to ultimately determine the presence or absence of an undesirable evaporative emission, as well as the functionality of the CV2 (e.g., 170) and the first check valve (CPV1) (e.g., 153).

[0110] At 450, the method 400 can include updating a vehicle operating parameter in response to the results of the evaporative emission test diagnostic. For example, in response to an indication of the absence of a significant undesirable evaporative emission, but further in response to an indication of the presence of a non-significant undesirable evaporative emission, updating a vehicle operating parameter can include adjusting an evaporative emission test schedule, and can further include illuminating a malfunction indicator light (MIL) on a vehicle dashboard alerting a vehicle driver that it is prudent to service the vehicle.

[0111] In some examples, in response to an absence of significant undesirable evaporative emissions and further in response to an indication of non-significant undesirable evaporative emissions, the vehicle operating conditions can be updated to CVV closed, CPV1 closed, and CPV2 open, as discussed above with respect to FIG. 3. Briefly, with the evaporative emissions system so configured, fuel tank vapors can travel from the fuel tank, through the entire fuel vapor canister (e.g., both the buffer and non-buffer regions) on the way to the engine air intake. In such examples, the vehicle system can be further configured to operate in the electrically operated mode as much as possible for the subsequent time of vehicle operation. In this way, fuel tank vapors can be carried through the entire canister and then can be carried to the engine air intake. However, with the engine off, any fuel tank vapors that are not adsorbed by the canister can be adsorbed via the AIS HC trap (e.g., 169) located in the air intake of the engine. In this way, undesirable evaporative emissions can be reduced even in the condition where an indication of non-significant undesirable evaporative emissions exists. Figure 3

[0112] Additionally, at 450, in response to an indication of an absence of significant undesirable evaporative emissions and further in response to an indication of an absence of non-significant undesirable evaporative emissions, the method 400 can include maintaining CPV1 closed, maintaining CPV2 closed, and commanding CVV open. By maintaining CPV1 and CPV2 closed, the fuel system and the evaporative emissions system can be sealed off from the engine air intake (and from the injectors). Further, by commanding CVV open, fuel vapors generated in the fuel tank (e.g., run loss fuel vapors, refueling vapors, or vapors caused by diurnal temperature fluctuations) can be carried to the fuel vapor canister (e.g., 104) for storage before exiting to the atmosphere. The method 400 can then end.

[0113] Returning to 435, if the indication of vacuum accumulation in the fuel system and the evaporative emissions system does not reach the predetermined threshold vacuum, the method 400 can proceed to 460. At 460, the method 400 can include indicating that CV2 is stuck closed, or that there is significant undesirable evaporative emissions in the fuel system and the evaporative emissions system. In other words, because CV2 is stuck closed, or because of significant undesirable evaporative emissions, the vacuum accumulation can be prevented from reaching the predetermined vacuum threshold. Thus, a final determination as to the source of the inability to reach the predetermined threshold vacuum can not be indicated at 460. Rather, the method 400 can proceed to 450. At 450, the method 400 can include storing the results of the evaporative emissions test diagnosis at the controller. As discussed above, and will be discussed below with respect to FIG. 5, the results of the evaporative emissions test diagnosis can be stored at the controller for use in diagnosing future evaporative emissions test diagnoses. Figures 5 to 8 ​Further in detail, the results of the evaporative emission test diagnostic procedure conducted in accordance with the method 400 can be used in some examples in combination with the results of an evaporative emission test diagnostic procedure (see Figures 5 to 7 ) conducted with the engine intake being under negative pressure to ultimately determine the cause of the failure to achieve the threshold vacuum during the evacuation of the evaporative emission system and fuel system in accordance with the method 400.

[0114] Continuing to 455, the method 400 can include commanding the closing of the CPV1 and commanding the opening of the CVV. By commanding the closing of the CPV1, the fuel system and the evaporative emission system can be sealed off from the engine intake (and from the injectors) as described above. Further, by commanding the opening of the CVV, fuel vapors generated in the fuel tank (e.g., run loss fuel vapors, refueling vapors, or vapors caused by diurnal temperature fluctuations) can be carried to the fuel vapor canister (e.g., 104) for storage before exiting to the atmosphere. The method 400 can then end.

[0115] Turning now to Figure 5 , another flowchart illustrating a high level example method 500 for performing an evaporative emission test diagnostic procedure on an evaporative emission control system (e.g., 154) and a fuel system (e.g., 106) is shown. More specifically, the method 500 can be used to conduct an evaporative emission test diagnostic procedure by having the engine spin without fueling to create an engine intake vacuum for testing. In this way, by conducting an evaporative emission test by having the engine spin without fueling to create an intake vacuum, a last indication of the absence of undesirable evaporative emissions and that a first check valve (CPV1) (e.g., 153) is not stuck closed can be indicated in response to a threshold vacuum being achieved during the conducting of the evaporative emission test diagnostic. Further, in response to an indication that the threshold vacuum was not achieved during the conducting of the evaporative emission test diagnostic, an indication that there is significant undesirable evaporative emissions or that the CPV1 is stuck closed can be indicated. Regardless of whether the threshold vacuum was indicated to be achieved, the results of the evaporative emission test diagnostic procedure can be stored at the controller as discussed in further detail below. Such a diagnostic can be desirable for vehicles such as HEVs or PHEVs (see Figures 1 to 2 ) where fueled engine operation is limited because the vehicle is capable of frequently propelling via electric power. It can be appreciated that the method 500 can be conducted with the vehicle in a non-operational state (e.g., key-off) or with the vehicle in operation but propelling only via electric power.

[0116] The method 500 will be described with reference to the systems described and Figures 1 to 2 shown herein, but it should be understood that similar methods can be applicable to other systems without departing from the scope of this disclosure. The method 500 can be performed by a controller such as Figure 1controller 166 and can be stored in non-transitory memory at the controller as executable instructions. Instructions for performing the method 500 and the remaining methods included herein can be executed by the controller based on instructions stored on the controller's memory and in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to Figures 1 to 2 The controller can employ engine, fuel system, and evaporative emission system actuators, such as a first canister purge valve (CPV1) (e.g., 158), a second canister purge valve (CPV2) (e.g., 165), a canister vent valve (CVV) (e.g., 172), a motor (e.g., 220), etc., in accordance with the methods below.

[0117] The method 500 begins at 505 and can include estimating and / or measuring vehicle conditions. The conditions can be estimated, measured, and / or inferred, and can include one or more vehicle conditions such as vehicle speed, vehicle location, etc., various engine conditions such as engine state, engine load, engine speed, A / F ratio, manifold air pressure, etc., various fuel system conditions such as fuel level, fuel type, fuel temperature, etc., various evaporative emission system conditions such as fuel vapor canister load, fuel tank pressure, etc., and various environmental conditions such as ambient temperature, humidity, barometric pressure, etc.

[0118] At 510, the method 500 can include indicating whether conditions for an unfueled engine spin evaporation emissions test are satisfied. For example, the conditions for an unfueled engine spin evaporation emissions test can include a threshold duration of time elapsed since a previous unfueled engine spin evaporation emissions test or other evaporation emissions test of the fuel system and / or evaporation emissions system, with a negative pressure in the engine intake relative to atmospheric pressure used to conduct the test. In another example, the conditions satisfied can include a threshold state of charge (SOC) of an on-board energy storage device (e.g., battery, capacitor, super capacitor, etc.). The threshold SOC can include a threshold SOC that enables use of the motor (e.g., 220) to evacuate the fuel system and evaporation emissions system without adversely affecting other vehicle operating parameters that can utilize energy provided via the on-board energy storage device. The conditions satisfied at 510 can additionally or alternatively include an indication of a threshold amount of time since the engine was last in operation. In some examples, the threshold amount of time can include an amount of time since the engine to any heat soak of the fuel system and / or evaporation emissions system can not adversely affect the unfueled engine spin evaporation emissions test. As discussed above, the unfueled engine spin evaporation emissions test can in some examples be conducted with the vehicle in operation but with the vehicle propelled via electric power, and / or with the vehicle not in operation (e.g., shut off). In examples where the unfueled engine spin evaporation emissions test is conducted with the vehicle not in operation, the method can include waking up the controller a predetermined time after a shut off event in order to conduct the test. In one example, the predetermined time can vary with a last engine start event, a duration of a last engine start event, environmental conditions such as temperature and / or humidity, etc. The conditions satisfied at 510 can additionally or alternatively include an indication that a purge event is not in progress. Additionally, in some examples, the conditions satisfied at 510 can include an indication that there was no undesirable evaporation emissions in the fuel system and / or evaporation emissions system previously, and an indication that CV1 (e.g., 153) was not stuck closed previously.

[0119] If at 510 it is indicated that the conditions for conducting the test are not satisfied, the method 500 can proceed to 515. At 515, the method 500 can include maintaining the current vehicle operating state. For example, at 515, the method 500 can include maintaining CPV1 in its current configuration, maintaining CPV2 in its current configuration, and maintaining CVV in its current configuration. Additionally, other engine system actuators such as a throttle, fuel injectors, etc. can be maintained in their current state. The method 500 can then end.

[0120] Returning to 510, in response to indicating that conditions for performing an unfueled engine spin evaporation emissions test are met, the method 500 can proceed to 520. At 520, the method 500 can include spinning the engine unfueled. For example, the motor (e.g., 220) can be actuated to cause the engine to rotate or spin unfueled (e.g., without fuel injection and without sparking). It can be appreciated that the engine can spin in a default or forward direction. By spinning the engine unfueled, a vacuum can be created in the engine intake (e.g., 23). The engine can spin at a predetermined speed (RPM), where the predetermined speed can include a speed at which an intake vacuum (e.g., a negative pressure relative to atmospheric pressure) is sufficient to perform a test for undesirable evaporation emissions. For example, the predetermined speed can include a speed at which a threshold vacuum is reached for a predetermined duration without undesirable evaporation emissions existing in the fuel system and evaporation emissions system. In some examples, the speed at which the engine spins unfueled can vary with the SOC of the on-board energy storage device.

[0121] With the electric supercharger activated at 520, the method 500 can proceed to 525. At 525, the method 500 can include commanding (actuating closed) the CVV, and commanding (actuating closed) the CPV1. Proceeding to 530, the method 500 can include commanding (actuating open) the CPV2. By commanding the CVV and CPV1 closed, while commanding the CPV2 open, the vacuum resulting from spinning the engine unfueled from the intake can be applied to the evaporation emissions system (e.g., 154) and the fuel system (e.g., 106). More specifically, by commanding the CVV closed at step 525, the evaporation emissions system and the fuel system can be sealed from atmospheric air. By commanding the CPV2 open at 530, the vacuum from the injectors can be applied to the sealed evaporation emissions system and fuel system. It can be appreciated that if the CPV1 were commanded open instead of the CPV2, the vacuum from the engine intake can draw fuel vapor from the fuel tank through the buffer (e.g., 104a) of the canister (e.g., 104) without carrying the fuel vapor through the non-buffer region (e.g., 104b), which can result in an increase in undesirable emissions as the fuel vapor can not be combusted in the engine as the engine is unfueled and not combusting air and fuel. Rather, by commanding the CPV2 open while the CPV1 is closed, the vacuum from the engine intake can draw the fuel tank vapor through the entire canister on its way to the engine intake. In this way, the fuel vapor can be effectively adsorbed by the canister, which can prevent or reduce the release of undesirable emissions into the atmosphere.

[0122] At 535, the method 500 can include monitoring for vacuum buildup in the evaporative emission system and the fuel system. For example, monitoring for vacuum buildup (e.g., a negative pressure relative to atmospheric pressure) can include monitoring pressure via a pressure sensor (e.g., 107) located in the fuel system and / or the evaporative emission system. In some examples, monitoring for vacuum buildup at 535 can be performed for a predetermined duration of time.

[0123] Continuing at 540, the method 500 can include indicating whether vacuum buildup as monitored by the pressure sensor during evacuation of the evaporative emission system and the fuel system is greater than a predetermined threshold vacuum (e.g., more negative than the predetermined threshold vacuum). In some examples, the predetermined threshold vacuum can vary with atmospheric pressure. For example, the predetermined threshold can include a vacuum level that decreases in response to decreasing atmospheric pressure, and a vacuum level that increases in response to increasing atmospheric pressure. The predetermined threshold can further be based on a predetermined diameter or area of an orifice through which undesirable evaporative emissions can escape from the fuel system and / or the evaporative emission system.

[0124] At 540, if it is indicated that vacuum buildup in the fuel system and the evaporative emission system has reached the predetermined threshold vacuum, the method 500 can proceed to 545. At 545, the method 500 can further include indicating that CV1 (e.g., 153) is not stuck closed. If CV1 were stuck closed, the pressure sensor (e.g., 107) would not register a change in pressure during evacuation of the fuel system and the evaporative emission system. In other words, CV1 must be functioning as needed in response to reaching the predetermined threshold vacuum. Furthermore, at 545, it can be indicated that there is not significant undesirable evaporative emissions originating from the fuel system and / or the evaporative emission system. For example, the method 500 can include indicating that there is not significant undesirable evaporative emissions originating from an orifice of a size of the predetermined diameter or area discussed above at 540, where the predetermined diameter or area corresponds to significant undesirable evaporative emissions. In some examples, significant undesirable evaporative emissions can include a diameter of an orifice corresponding to 0.04” or greater.

[0125] Continuing at 550, the method 500 can include closing the CPV2 to isolate the fuel system and evaporative emission system from the atmosphere and the engine intake, and monitoring pressure bleed off in the fuel system and evaporative emission system. Further, at 550, the method 500 can include actuating a closing (deactivating) motor to spin the engine to a standstill. With the fuel system and evaporative emission system isolated from the atmosphere and the engine intake, pressure in the fuel system and evaporative emission system can be monitored by a pressure sensor (e.g., 107). In some examples, the pressure can be monitored for a predetermined duration. If the pressure in the fuel system and evaporative emission system reaches a predetermined pressure rise threshold, or if a pressure bleed off rate exceeds a predetermined pressure rise rate threshold, then a non-significant undesirable evaporative emission can be indicated. However, if the pressure does not reach the predetermined pressure rise threshold, or if the pressure bleed off rate does not exceed the predetermined pressure rise rate threshold, then an absence of a non-significant undesirable evaporative emission can be indicated. Although step 540 includes indicating an absence of a significant undesirable evaporative emission, it can be appreciated that at step 550, indicating an absence or presence of a non-significant undesirable evaporative emission includes an undesirable evaporative emission originating from an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. For example, at 550, the non-significant undesirable evaporative emission can be indicated as corresponding to an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. Thus, step 550 includes testing for an absence or presence of a non-significant undesirable evaporative emission by comparing a pressure change in the fuel system or evaporative emission system after the fuel system and evaporative emission system is evacuated to a reference pressure change.

[0126] Proceeding to step 555, the method 500 can include storing results of the evaporative emission test diagnostic procedure at the controller. As will be discussed in further detail below, results of the evaporative emission test diagnostic procedure conducted in accordance with the method 500 can be used in conjunction with results of an evaporative emission test diagnostic procedure conducted with positive pressure in the intake of the engine (see Figures 3 to 4 ) in some examples in order to ultimately determine an absence or presence of an undesirable evaporative emission, and functionality of the CV2 (e.g., 170) and the first check valve (CV1) (e.g., 153).

[0127] At 555, the method 500 can include updating vehicle operating parameters in response to results of the evaporative emission test diagnostic. For example, in response to an indication of an absence of a significant undesirable evaporative emission, but further in response to an indication of a presence of a non-significant undesirable evaporative emission, updating vehicle operating parameters can include adjusting an evaporative emission test schedule, and can further include illuminating a malfunction indicator light (MIL) on a vehicle dashboard alerting a vehicle driver that it is prudent to service the vehicle.

[0128] In some examples, in response to an absence of significant undesirable evaporative emissions and further in response to an indication of non-significant undesirable evaporative emissions, the vehicle operating conditions can be updated such that the evaporative emissions system can be configured with the CVV closed, the CPV1 closed, and the CPV2 open. With the evaporative emissions system so configured, fuel tank vapors can travel from the fuel tank, through the entire fuel vapor canister (e.g., both the buffer and non-buffer regions) on the way to the engine air intake. In such examples, the vehicle system can be further configured to operate in an electric mode of operation as much as possible during subsequent times of vehicle operation. In this way, fuel tank vapors can be carried through the entire canister and then can be carried to the engine air intake. However, with the engine off, any fuel tank vapors that are not adsorbed by the canister can be adsorbed via the AIS HC trap (e.g., 169) located in the air intake of the engine. In this way, even in the condition where there is an indication of non-significant undesirable evaporative emissions, undesirable evaporative emissions can be reduced. More specifically, if there is a small (e.g., non-significant) source of undesirable evaporative emissions, by carrying the fuel tank vapors through the entire fuel vapor canister on the way to the engine air intake via the open CPV2 (and closed CVV), it is more likely that the vapors can travel to the engine air intake as discussed, rather than being released to the atmosphere, because the flow resistance on the way to the engine air intake is less than through the small source.

[0129] Additionally, at 555, in response to an indication of an absence of significant undesirable evaporative emissions and further in response to an indication of an absence of non-significant undesirable evaporative emissions, the method 500 can include maintaining the CPV1 closed, maintaining the CPV2 closed, and commanding the CVV open. By maintaining the CPV1 and CPV2 closed, the fuel system and the evaporative emissions system can be sealed off from the engine air intake (and from the injectors). Further, by commanding the CVV open, fuel vapors generated in the fuel tank (e.g., run loss fuel vapors, refueling vapors, or vapors caused by diurnal temperature fluctuations) can be carried to the fuel vapor canister (e.g., 104) for storage before exiting to the atmosphere. The method 500 can then end.

[0130] Returning to 540, if the indication of vacuum buildup in the fuel system and the evaporative emissions system does not reach a predetermined threshold vacuum, the method 500 can proceed to 565. At 565, the method 500 can include indicating that CV1 is stuck closed, or that there is significant undesirable evaporative emissions in the fuel system and the evaporative emissions system. In other words, because CV1 is stuck closed, or because of significant undesirable evaporative emissions, the vacuum buildup can be prevented from reaching the predetermined vacuum threshold. Accordingly, a final determination as to the source of the inability to reach the predetermined threshold vacuum can not be indicated at 565. Rather, the method 500 can proceed to 570. At 570, the method 500 can include commanding the closing (actuating the closing) of CPV2, and can include deactivating the motor to spin the engine to a standstill. Proceeding to 555, the method 500 can include storing the results of the evaporative emissions test diagnosis at the controller, and can further include updating the vehicle regime. Updating the vehicle regime at 555 can include scheduling a test for undesirable evaporative emissions in a condition of positive pressure in the intake of the engine relative to atmospheric pressure, in order to determine whether CV2 is stuck closed, or whether there is significant undesirable evaporative emissions, as discussed above with respect to Figures 3 to 4 The method 500 can then end.

[0131] Turning now to Figure 6 , a flowchart illustrating a high-level example method 600 for performing an evaporative emissions test diagnostic procedure on an evaporative emissions control system (e.g., 154) and a fuel system (e.g., 106) is shown. More specifically, the method 600 can be used to conduct an evaporative emissions test diagnostic procedure in response to an indication that conditions for an evaporative emissions test in a natural intake (intake manifold vacuum) condition are met, where the engine is operating to combust air and fuel. In this way, by conducting the evaporative emissions test in a natural intake condition where the engine is in operation to combust air and fuel (fueled engine operation), an indication of the absence of undesirable evaporative emissions and that a first check valve (CV1) (e.g., 153) is not stuck closed can be finally indicated in response to a threshold vacuum being reached during the evaporative emissions test diagnostic. Further, in response to an indication that the threshold vacuum is not reached during the evaporative emissions test diagnostic, an indication that there is significant undesirable emissions, or that CV1 is stuck closed, can be indicated. Regardless of whether the threshold vacuum is indicated to be reached, the results of the evaporative emissions test diagnostic procedure can be stored at the controller, as discussed in further detail below.

[0132] The method 600 will be described with reference to the system described and Figure 1 shown herein, but it should be understood that similar methods can be applicable to other systems without departing from the scope of this disclosure. The method 600 can be performed by a controller, such as Figure 1the controller 166 in FIG. 1, and can be stored in non-transitory memory at the controller as executable instructions. Instructions for performing the method 600 and the remaining methods included herein can be executed by the controller based on instructions stored on memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to FIG. 1. According to the method below, the controller can employ fuel system and evaporative emission system actuators, such as a first canister purge valve (CPV1) (e.g., 158), a second canister purge valve (CPV2) (e.g., 165), a canister vent valve (CVV) (e.g., 172), etc. Figure 1 The controller 166 in FIG. 1 can be configured to perform the method 600. The controller 166 can be configured to perform the method 600 by executing instructions stored on non-transitory memory of the controller 166, and the instructions can be stored in non-transitory memory at the controller as executable instructions. Instructions for performing the method 600 and the remaining methods included herein can be executed by the controller based on instructions stored on memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to

[0133] The method 600 begins at 605 and can include estimating and / or measuring vehicle operating conditions. The operating conditions can be estimated, measured, and / or inferred, and the operating conditions can include one or more vehicle conditions such as vehicle speed, vehicle location, etc., various engine conditions such as engine state, engine load, engine speed, A / F ratio, manifold air pressure, etc., various fuel system conditions such as fuel level, fuel type, fuel temperature, etc., various evaporative emission system conditions such as fuel vapor canister load, fuel tank pressure, etc., and various environmental conditions such as ambient temperature, humidity, barometric pressure, etc.

[0134] At 610, the method 600 can include determining whether conditions for an evaporative emission test under natural intake (intake manifold vacuum) are satisfied, where the engine is operating to combust air and fuel. For example, the conditions for the evaporative emission test under natural intake can include an indication that a manifold air pressure (MAP) is less than a barometric pressure (BP) or atmospheric pressure by a predetermined threshold amount. In some examples, the conditions satisfied at 610 can include that the MAP is less than the BP by the predetermined threshold amount for a predetermined duration of time. In some examples, the conditions satisfied at 610 can further include an indication that the evaporative emission control system and fuel system have not been diagnosed for evaporative emission testing under natural intake conditions during the current drive cycle. In some examples, the conditions satisfied at 610 can further include an indication that a purge event is not in progress. Additionally, in some examples, the conditions satisfied at 610 can include an indication that there has not been an undesirable evaporative emission in the fuel system and / or evaporative emission system previously, and an indication that the CV1 (e.g., 153) has not been stuck closed previously.

[0135] If at 610 it is indicated that the conditions of the evaporative emission test diagnostic procedure under natural intake are not satisfied, the method 600 can proceed to 615. At 615, the method 600 can include maintaining the current vehicle operating conditions. For example, at 615, the method 600 can include maintaining CPV1 in its current configuration, maintaining CPV2 in its current configuration, and maintaining CVV in its current configuration. In addition, other engine system actuators, such as the throttle, fuel injectors, etc., can be maintained in their current state. The method 600 can then end.

[0136] Returning to 610, if it is indicated that the conditions of the evaporative emission test diagnostic procedure are satisfied, the method 600 can proceed to 620. At 620, the method 600 can include commanding the closure (actuating closed) of the CVV. Proceeding to 625, the method 600 can include commanding the opening (actuating open) of CPV1. Although not explicitly shown, CPV2 can be maintained closed or commanded closed at 620. By commanding the closure of the CVV and the opening of CPV1, with CPV2 closed, the vacuum available from the intake manifold under natural intake conditions can be applied to the evaporative emission system (e.g., 154) and the fuel system (e.g., 106). More specifically, by commanding the closure of the CVV at step 620, the evaporative emission system and the fuel system can be sealed from atmospheric air. By commanding the opening of CPV1 at 625, the vacuum available from the intake manifold can be applied to the sealed evaporative emission system and fuel system.

[0137] Proceeding to 630, the method 600 can include monitoring the vacuum buildup in the evaporative emission system and the fuel system. For example, as discussed above, monitoring the vacuum buildup (e.g., negative pressure relative to atmospheric pressure) can include monitoring the pressure via a pressure sensor (e.g., 107) located in the fuel system and / or the evaporative emission system. In some examples, monitoring the vacuum buildup at 630 can be performed for a predetermined duration of time.

[0138] Accordingly, proceeding to 635, the method 600 can include indicating whether the vacuum buildup as monitored by the pressure sensor during the evacuation of the evaporative emission system and the fuel system is greater than a predetermined threshold vacuum. In some examples, the predetermined threshold vacuum can be a function of atmospheric pressure. For example, the predetermined threshold can include a vacuum level that decreases in response to decreasing atmospheric pressure, and a vacuum level that increases in response to increasing atmospheric pressure. The predetermined threshold vacuum can be further based on a predetermined diameter or area of an orifice through which undesirable evaporative emissions can escape from the fuel system and / or the evaporative emission system.

[0139] At 635, if the indication of vacuum buildup in the fuel system and the evaporative emissions system has reached a predetermined threshold vacuum, the method 600 can proceed to 640. At 640, the method 600 can include indicating that the CV1 (e.g., 153) is not stuck closed or substantially closed. If the CV1 is stuck closed, the pressure sensor (e.g., 107) will not record a change in pressure during the evacuation of the fuel system and the evaporative emissions system. In other words, the CV1 must be functioning as needed in response to reaching the predetermined threshold vacuum. Further, at 640, it can be indicated that there is not a significant undesirable evaporative emission originating from the fuel system and / or the evaporative emissions system. For example, the method 600 can include indicating that there is not a significant undesirable evaporative emission originating from an orifice of a predetermined diameter or area, where the predetermined diameter or area corresponds to a significant undesirable evaporative emission. In some examples, the significant undesirable evaporative emission can include a hole diameter of 0.04” or greater.

[0140] Proceeding to 645, the method 600 can include closing the CPV1 to isolate the fuel system and the evaporative emissions system from the atmosphere and the engine intake, and monitoring a pressure bleed down in the fuel system and the evaporative emissions system. Again, the pressure can be monitored by the pressure sensor (e.g., 107). In some examples, the pressure can be monitored for a predetermined duration. If the pressure in the fuel system and the evaporative emissions system reaches a predetermined pressure rise threshold, or if a pressure bleed down rate exceeds a predetermined pressure rise rate threshold, it can be indicated that there is a non-significant undesirable evaporative emission. However, if the pressure does not reach the predetermined pressure rise threshold during the predetermined duration, or if the pressure bleed down rate does not exceed the predetermined pressure rise rate threshold, it can be indicated that there is not a non-significant undesirable evaporative emission. Although step 640 includes indicating that there is not a significant undesirable evaporative emission, it can be appreciated that, at step 645, indicating the presence or absence of a non-significant undesirable evaporative emission includes undesirable evaporative emissions originating from an orifice size that is less than an orifice size corresponding to a significant undesirable evaporative emission. For example, at 645, the non-significant undesirable evaporative emission can be indicated as corresponding to an orifice size that is substantially less than an orifice size corresponding to a significant undesirable evaporative emission. Thus, step 645 includes testing for the presence or absence of a non-significant undesirable evaporative emission by comparing a change in pressure in the fuel system or the evaporative emissions system after evacuating the fuel system and the evaporative emissions system to a reference change in pressure.

[0141] Proceeding to step 650, the method 600 can include storing results of the evaporative emission test diagnostic procedure at the controller. As will be discussed in further detail below, results of the evaporative emission test diagnostic procedure conducted in accordance with the method 600 can be used in conjunction with results of an evaporative emission test diagnostic procedure conducted under a boost condition (engine off or engine on) (see Figures 3 to 4 ) in some examples in order to ultimately determine the presence or absence of undesirable evaporative emissions, as well as the functionality of the CV2 (e.g., 170) and the first check valve (CV1) (e.g., 153).

[0142] Further, at 650, the method 600 can include updating vehicle operating parameters in response to results of the evaporative emission test diagnostic. For example, in response to an indication of the absence of significant undesirable evaporative emissions, but further in response to an indication of the presence of non-significant undesirable evaporative emissions, updating vehicle operating parameters can include adjusting an evaporative emission test schedule, and can further include illuminating a malfunction indicator light (MIL) on a vehicle dashboard alerting a vehicle operator that it is prudent to service the vehicle.

[0143] In some examples, in response to an indication of the absence of significant undesirable evaporative emissions and further in response to an indication of the presence of non-significant undesirable evaporative emissions, updating vehicle operating parameters, the evaporative emission system can be configured with the CVV closed, the CPV1 closed, and the CPV2 open, as discussed above. In short, with the evaporative emission system so configured, fuel tank vapors can travel from the fuel tank, through the entire fuel vapor canister (e.g., both buffer and non-buffer regions) on the way to the engine air intake. In such examples, the vehicle system can be further configured to operate as electrically as possible during subsequent times of vehicle operation. In this way, fuel tank vapors can be carried through the entire canister and then can be carried to the engine air intake. However, with the engine off, any fuel tank vapors that are not adsorbed by the canister can be adsorbed via the AIS HC trap (e.g., 169) located in the air intake of the engine. In this way, undesirable evaporative emissions can be reduced even in the condition indicating the presence of non-significant undesirable evaporative emissions.

[0144] Additionally, at 650, in response to the absence of an indication of significant undesirable evaporative emissions and further in response to the absence of an indication of non-significant undesirable evaporative emissions, the method 600 can include maintaining CPV1 closed, maintaining CPV2 closed, and commanding the opening of CVV. By maintaining CPV1 and CPV2 closed, the fuel system and evaporative emissions system can be sealed off from the engine air intake (and from the injectors). Further, by commanding the opening of CVV, fuel vapors generated in the fuel tank (e.g., run loss fuel vapors, refueling vapors, or vapors caused by diurnal temperature fluctuations) can be carried to a fuel vapor filter canister (e.g., 104) for storage before exiting to the atmosphere. The method 600 can then end.

[0145] Turning now to Figure 7 , a flowchart of a high-level example method 700 for performing an evaporative emissions test diagnostic procedure under both a boosted condition and a naturally aspirated condition is shown. In other words, the method 700 includes dual test monitoring. The method 700 includes evacuating the fuel system and evaporative emissions system via a first check valve (CV1) (e.g., 153) in a first condition, and evacuating the fuel system and evaporative emissions system via a second check valve (CV2) (e.g., 170) in a second condition. Thus, the presence or absence of significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system, and whether one of the first check valve or the second check valve is stuck substantially closed, can be indicated based on the vacuum levels reached during evacuation of the fuel system and evaporative emissions system in both the first condition and the second condition. Further, after evacuation of the fuel system and evaporative emissions system via CV1 or CV2, the fuel system and evaporative emissions system can be sealed off from the engine air intake and from the atmosphere, and a pressure bleed down test can be performed in order to indicate the presence or absence of non-significant undesirable evaporative emissions.

[0146] The method 700 will be described with reference to the system described and Figures 1 to 2 shown herein, but it should be understood that similar methods can be applicable to other systems without departing from the scope of the present disclosure. The method 700 will be further described with reference to the methods described and Figures 3 to 6 shown herein. The method 700 can be performed by a controller, such as the controller 166 in Figure 1 and can be stored as executable instructions in a non-transitory memory at the controller. The instructions for performing the method 700 and the remaining methods included herein can be executed by the controller based on instructions stored on a memory of the controller in conjunction with inputs from sensors of the engine system, such as described above with reference to Figure 1The controller executes actions based on signals received by the described sensor. According to the method described below, the controller may employ fuel system and evaporative emission system actuators, such as a first filter canister flush valve (CPV1) (e.g., 158), a second filter canister flush valve (CPV2) (e.g., 165), a filter canister vent valve (CVV) (e.g., 172), a motor (e.g., 220), an electric booster (e.g., 155), etc.

[0147] Method 700 begins at 705 and may include estimating and / or measuring vehicle operating conditions. Operating conditions may be estimated, measured, and / or inferred, and operating conditions may include one or more vehicle conditions such as vehicle speed, vehicle position, etc., various engine conditions such as engine status, engine load, engine speed, A / F ratio, manifold air pressure, etc., various fuel system conditions such as fuel level, fuel type, fuel temperature, etc., various evaporative emission system conditions such as fuel vapor filter load, fuel tank pressure, etc., and various environmental conditions such as ambient temperature, humidity, atmospheric pressure, etc.

[0148] Proceeding to 710, method 700 may include indicating whether the conditions for a diagnostic test of evaporative emissions under boost conditions are met. In this example method 700, it can be understood that the conditions met at 710 may include meeting the engine shutdown test (see...). Figure 3 Step 310) or engine start test (see Figure 4 The condition in step 410) is that, during the engine shutdown test, the electric supercharger is used to provide a boost pressure of positive intake pressure relative to atmospheric pressure. Since the conditions for indicating whether an engine shutdown test or engine start-up test is met have already been described in detail above, these conditions will not be repeated here for the sake of brevity.

[0149] If at 710 the conditions for the evaporative emissions test diagnostic procedure under boost conditions (engine start or engine stop) are indicated, then method 700 can proceed to 715. At 715, method 700 may include, according to the above description... Figures 3 to 4 The method described in detail involves conducting evaporative emission tests under boost conditions. For example, if the conditions for conducting an engine shut-off boost test are met as indicated at 710, then this can be utilized... Figure 3 Method 300 is shown at point 710. Alternatively, if the conditions for performing an engine start-up boost test are indicated at point 710, then the following can be used: Figure 4 Method 400. As discussed above, under boost conditions with the engine off ( Figure 3 Or under boost conditions during engine start-up ( Figure 4The results of the test diagnosis can be stored at the controller for use in conjunction with the results of the evaporative emission test diagnosis procedure conducted under conditions of negative pressure in the engine intake relative to atmospheric pressure, discussed in further detail below, after the evaporative emission test diagnosis procedure is conducted.

[0150] Accordingly, after the evaporative emission test diagnosis procedure is conducted under boosted conditions (engine start or engine off) and the results are stored at the controller according to the method 300 shown in Figure 3 or the method 400 shown in Figure 4 Method 700 can proceed to 720 after the evaporative emission test diagnosis procedure is conducted under boosted conditions (engine start or engine off) and the results are stored at the controller according to the method 300 shown in Figure 5 or the method 400 shown in Figure 6 Since the conditions for indicating whether to conduct an unfueled engine operation test or a fueled engine operation test have been described in detail above, these conditions will not be repeated here for the sake of brevity.

[0151] If the conditions for the evaporative emission test diagnosis procedure under natural intake conditions (fueled engine operation or unfueled engine operation) are indicated as not being met at 720, method 700 can proceed to 725. At 725, method 700 can include maintaining the vehicle operating conditions until the conditions for conducting the evaporative emission test diagnosis under natural intake conditions are indicated as being met. For example, the state of the evaporative emission system actuators (e.g., CPV1, CPV2, CVV), the fuel system actuators (e.g., fuel injectors, etc.), the engine operating conditions (air-fuel ratio, spark timing, etc.) can be maintained.

[0152] Accordingly, proceeding to 726, method 700 can include indicating whether a threshold duration of time has elapsed since the evaporative emission test was conducted under boosted conditions, which can include an engine start condition or an engine off condition. For example, consider the case where the vehicle is in a key-off condition and the method 300 shown in Figure 3 is conducted under an engine off boosted condition. In one example, another evaporative emission test can be conducted during the same key-off condition, this time an unfueled engine spin to conduct the method 400 shown in Figure 5The illustrated method 500 conducts the tests in natural intake conditions. This series of tests can be conducted, for example, in response to a battery charge amount sufficient to conduct both an engine off test in boosted conditions and an unfueled engine spin test using natural intake. In this example, both tests can be conducted for a threshold duration under some examples.

[0153] However, there can be instances where an engine off test in boosted conditions is conducted during a key-off condition (400), and then the vehicle enters an on condition before conducting the test in natural intake conditions during the same key-off condition. In this example, the natural intake test using an unfueled engine spin (402) or the natural intake test using a fueled engine operation (404) can be conducted for a threshold duration as long as the threshold duration has not elapsed. Figure 3 Figure 5 Figure 6

[0154] Similarly, there can be instances where an evaporative emission test in boosted conditions is conducted during an on condition, with the engine in operation (406). Before conducting the test in natural intake conditions during the same on condition, if the vehicle is turned off (e.g., key-off condition), the evaporative emission test can be conducted in natural intake conditions with the engine off (408) for a threshold duration as long as the threshold duration has not elapsed. These examples are intended to be illustrative. Figure 4 Figure 5

[0155] In other words, for a dual monitoring test that includes testing for undesirable evaporative emissions in boosted conditions (engine on or engine off) and testing for undesirable evaporative emissions in natural intake conditions (fueled or unfueled engine operation), the tests can not be limited to both being conducted during the same on condition or the same key-off condition. Rather, the dual test monitoring can include one test (e.g., boosted operation) conducted while the vehicle is in operation (on), and the other test (e.g., natural intake) conducted after the vehicle has been deactivated (key-off) for a threshold duration as long as the threshold duration has not elapsed. In another example, the dual test monitoring can include one test (e.g., boosted operation) conducted while the vehicle is deactivated (key-off), and the other test (e.g., natural intake) conducted after the vehicle has been activated (on) for a threshold duration as long as the threshold duration has not elapsed. Figure 7 The illustrated dual monitoring tests can include both tests being conducted in the same on condition (e.g., boosted operation and natural intake), or can include both tests being conducted in the same key-off condition (e.g., boosted operation and natural intake) for a threshold duration as long as the threshold duration has not elapsed.

[0156] Additionally, Figure 7 The illustrated dual monitoring tests can include both tests being conducted in the same on condition (e.g., boosted operation and natural intake), or can include both tests being conducted in the same key-off condition (e.g., boosted operation and natural intake) for a threshold duration as long as the threshold duration has not elapsed.

[0157] ​​​​​In some examples, the threshold duration can include, for example, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 12 hours, 14 hours, or 24 hours. Thus, if at 726, it is not indicated that the threshold duration has elapsed, the method 700 can return to 720, where it can be evaluated whether the conditions for conducting the natural intake test (either fueled or unfueled engine operation) are met. Alternatively, in response to an indication that the threshold duration has elapsed, the method 700 can proceed to 727, and can include aborting the dual test monitoring. In such examples, the fact that the dual test monitoring was aborted can be stored at the controller as a flag at the controller, and another dual test monitoring can be scheduled at the next available opportunity.

[0158] Returning to 720, if it is indicated that the conditions for the evaporative emission test diagnostic procedure under natural intake conditions are met, the method 700 can proceed to 730. At 730, the method 700 can include conducting the evaporative emission test diagnostic procedure under natural intake (either fueled engine operation or unfueled engine operation) according to the method shown above with respect to Figures 5 to 6

[0159] After conducting the test under natural intake conditions, which can include fueled engine operation Figure 6 ) or unfueled engine operation Figure 5 , the method 700 can proceed to 735.

[0160] Thus, at 735, the method 700 can include indicating the results of the dual test monitoring. In particular, the results from the evaporative emission test diagnostic procedure under both boosted conditions and natural intake conditions can be analyzed and interpreted by, for example, the controller, in order to indicate whether CV1 (e.g., 153) is stuck closed, whether CV2 (e.g., 170) is stuck closed, and whether there is an undesirable evaporative emission in the evaporative emission system (e.g., 154) and / or the fuel system (e.g., 106). In some examples, the results of the dual test monitoring can be interpreted / analyzed with respect to a lookup table stored at the controller. Figure 8 One such example lookup table is shown.

[0161] Turning to Figure 8 , an example lookup table 800 for interpreting (analyzing) the results from the dual test monitoring is shown. Four possible results from the dual test monitoring are indicated with the letters A, B, C, and D. The four possible results will be described accordingly herein.

[0162] ​Result A can include an example in which the predetermined vacuum threshold is reached in both the boost condition (engine start or engine off) and the natural intake condition (fuelled engine operation or un-fuelled engine operation). In this example result A, it can be indicated that neither CV1 nor CV2 are stuck closed, and that there is no significant undesirable evaporative emissions in the fuel system and evaporative emissions system (e.g., a 0.04” or larger orifice diameter size). If one of the valves is stuck closed, the predetermined vacuum would not be reached in a condition where the fuel system and evaporative emissions are being evacuated via a route that includes the stuck closed valve.

[0163] Result B can include an example in which the predetermined vacuum threshold is not reached in the boost condition (engine start or engine off), and additionally the predetermined vacuum threshold is not reached in the natural intake condition (fuelled or un-fuelled engine operation). In such an example result B, it can be indicated with high probability that neither CV1 nor CV2 are stuck closed, but the reason that the predetermined vacuum threshold is not reached in both the boost condition and the natural intake condition is because there is significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system. For example, it can be a low probability event that both CV1 and CV2 are stuck closed. Therefore, if the tests in both the boost condition and the natural intake condition indicate that the predetermined vacuum threshold cannot be reached, the most likely explanation is that there is significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system. Thus, in response to indicating result B after conducting the dual test monitoring, a technician can be directed to first look for the presence of undesirable evaporative emissions. In this example scenario, if the technician does not find significant undesirable evaporative emissions, the cause of result B can be that both CV1 and CV2 are stuck closed.

[0164] Result C can include examples where a predetermined vacuum threshold is reached under boost conditions (engine start or engine stop), but not under naturally aspirated conditions (engine operation with or without fuel). In other words, a predetermined negative pressure is not reached when the fuel system and evaporative emission system are purged during naturally aspirated operation, but is reached when the pressure is reduced during boosted operation. In such an example result C, it can be indicated that CV2 is not stuck shut, CV1 is stuck shut, and there are no significant unwanted evaporative emissions in the fuel system and evaporative emission system. More specifically, because the predetermined vacuum threshold is reached under one condition, there cannot be significant unwanted evaporative emissions, otherwise the predetermined vacuum threshold would not be reached. Furthermore, because the predetermined vacuum threshold is not reached under one condition (in this example, under naturally aspirated conditions), it can be definitively determined that CV1 is stuck shut. Therefore, for example, technicians can be instructed to alleviate a stuck shut CV1 instead of searching for sources of significant unwanted evaporative emissions in the fuel system and evaporative emission system.

[0165] Result D can include examples where a predetermined vacuum threshold is not reached under boost conditions (engine start or engine stop), but is reached under naturally aspirated conditions (engine operation with or without fuel). In other words, a predetermined negative pressure is not reached when the fuel system and evaporative emission system are purged during boosted operation, but is reached when the pressure is reduced during naturally aspirated operation. In such an example, result D can indicate that CV2 is stuck shut, CV1 is not stuck shut, and there are no significant unwanted evaporative emissions in the fuel system and evaporative emission system. For example, similar to result C, because the predetermined vacuum threshold is reached under one condition, there cannot be significant unwanted evaporative emissions, otherwise the predetermined vacuum threshold would not be reached. Furthermore, because the predetermined vacuum threshold is not reached under one condition (boosted in this example), it can be concluded that CV2 is stuck essentially shut. Therefore, for example, technicians can be instructed to alleviate the stuck shut of CV2 instead of searching for sources of unwanted evaporative emissions in the fuel system and evaporative emission system.

[0166] In summary, example lookup table 800 can be used to explain the interpretation based on... Figure 7 The results of the dual-test monitoring performed by method 700 are shown. Therefore, return to... Figure 7 Step 735, in response to the result of dual test monitoring indicated via, for example, lookup table 800, method 700 can proceed to Figure 9 The method 900 shown is in Figure 9The filter canister purge operation can be adjusted based on the results of the dual test monitoring. In addition, in response to an indication that CV1 or CV2 is stuck closed, or in response to an indication of undesirable evaporative emissions, a malfunction indicator light (MIL) can be illuminated, for example, on the vehicle's dashboard, alerting the vehicle's driver to service the vehicle, and can further include an indication of the cause of the MIL.

[0167] Returning to 710, if the conditions indicating the evaporative emission test diagnostic procedure under boosted conditions (engine start or engine off) are not met, the method 700 can proceed to 740. At 740, the method 700 can include indicating whether the conditions for conducting the evaporative emission test diagnostic procedure under natural intake conditions (fueled engine operation or unfueled engine operation) are met. Figure 5 The case where the conditions for conducting the evaporative emission test under natural intake conditions for unfueled engine operation are met has been described at step 510 of the method 500. Figure 6 The case where the conditions for conducting the evaporative emission test under natural intake conditions for fueled engine operation are met has been described at step 610 of the method 600. Accordingly, for the sake of brevity, these conditions will not be reiterated here.

[0168] If at 740 it is indicated that the conditions for the evaporative emission test diagnostic procedure under natural intake conditions (unfueled or fueled engine operation) are met, the method 700 can proceed to 745. At 745, the method 700 can include conducting the evaporative emission test under natural intake according to the method (unfueled engine spin) described in detail above with respect to the method 500, or the method (fueled engine operation) described above with respect to the method 600. Figure 5 The results of the test diagnosis can be stored at the controller after the evaporative emission test under natural intake conditions is conducted, as discussed above, for utilization in conjunction with the results of the evaporative emission test diagnostic procedure conducted under boosted conditions. Figure 6 The results of the test diagnosis can be stored at the controller after the evaporative emission test under natural intake conditions is conducted, as discussed above, for utilization in conjunction with the results of the evaporative emission test diagnostic procedure conducted under boosted conditions.

[0169] Accordingly, after the evaporative emission test diagnostic procedure under natural intake conditions is conducted and the results are stored at the controller, the method 700 can proceed to 750. At 750, the method 700 can include indicating whether the conditions for the evaporative emission test diagnostic procedure under boosted conditions (engine start or engine off conditions) are met. For example, it can be appreciated that the conditions met at 750 can include meeting the engine off test (see step 310 of the method 300) or the engine start test (see step 410 of the method 400). Figure 3 The results of the test diagnosis can be stored at the controller after the evaporative emission test under natural intake conditions is conducted, as discussed above, for utilization in conjunction with the results of the evaporative emission test diagnostic procedure conducted under boosted conditions. Figure 4the conditions of step 410) of the engine-off test, the electric supercharger is used to provide a boost condition of positive intake air pressure relative to atmospheric pressure. Since the conditions for indicating whether the conditions for conducting an engine-off test or an engine-on test are satisfied have been described in detail above, these conditions will not be repeated here for the sake of brevity.

[0170] If at 750 it is indicated that the conditions of the evaporative emission test diagnostic procedure under boost conditions are not satisfied, the method 700 can proceed to 755. At 755, the method 700 can include maintaining the vehicle operating conditions until it is indicated that the conditions for conducting an evaporative emission test diagnostic under a boost condition (engine-on or engine-off condition) are satisfied. For example, the state of the evaporative emission system actuators (e.g., CPV1, CPV2, CVV), the fuel system actuators (e.g., fuel injectors, etc.), the engine operating conditions (air-fuel ratio, spark timing, etc.) can be maintained.

[0171] Accordingly, proceeding to 756, the method 700 can include indicating whether a threshold duration has elapsed since the evaporative emission test was conducted under natural intake conditions, which can include a fueled engine operation or an unfueled engine operation. Examples of threshold durations have been provided above at step 726 of the method 700, and are equally applicable to step 756. Accordingly, detailed descriptions of the conditions related to threshold durations will not be repeated here for the sake of brevity.

[0172] Accordingly, if at 756 it is not indicated that the threshold duration has elapsed, the method 700 can return to 750, where it can evaluate whether the conditions for conducting an unwanted evaporative emission boost test (engine-on or engine-off condition) are satisfied. Alternatively, in response to an indication that the threshold duration has elapsed, the method 700 can proceed to 757, and can include aborting the dual test monitoring. In such examples, the fact that the dual test monitoring was aborted can be stored at the controller as a flag at the controller, and another dual test monitoring can be scheduled at the next available opportunity.

[0173] Returning to 750, if it is indicated that the conditions of the evaporative emission test diagnostic procedure under boost conditions are satisfied, the method 700 can proceed to 760. At 760, the method 700 can include conducting an evaporative emission test procedure under boost conditions according to the methods described above with respect to Figure 3 Figure 4 As discussed above, following the conduct of the evaporative emission test diagnostic procedure under boost conditions (engine-on or engine-off condition), the results of the test diagnostic can be stored at the controller for utilization in conjunction with the results of the evaporative emission test diagnostic procedure conducted under natural intake conditions during the same drive cycle.​

[0174] Therefore, proceeding to 765, method 700 may include indicating the results of dual test monitoring. As discussed above regarding step 735 of method 700, this can be achieved via a controller based on a lookup table (such as...). Figure 8 The lookup table shown (800) is used to analyze and interpret the results of the evaporative emissions test diagnostic procedure under both naturally aspirated conditions (engine operation with or without fuel) and boosted conditions (engine start or engine stop). To avoid redundancy, the details of the previous steps will not be repeated here. Figure 8 The description is not exhaustive, but it is understandable, as discussed in detail above, that at step 865, it can be based on... Figure 8 The lookup table shown explains the results of the dual test monitoring. Furthermore, as discussed above, in response to an indication that CV1 or CV2 is stuck shut, or in response to an indication of unwanted evaporative emissions, the malfunction indicator lamp (MIL) can, for example, illuminate on the vehicle's dashboard to alert the driver to vehicle maintenance, and may further include the reason for indicating the MIL. In response to indicating the results of the dual test monitoring at 765, method 700 can proceed to... Figure 9 The method 900 shown is in Figure 9 The filter tank flushing operation can be adjusted based on the results of dual test monitoring.

[0175] Turn now Figure 9 A flowchart of a high-level example method 900 for performing a fuel vapor filter canister flushing operation is shown. More specifically, method 900 can be performed from method 700 and may include flushing fuel vapor stored in the fuel vapor filter canister under selected engine operating conditions by: commanding the opening of a first filter canister flushing valve (CPV1), commanding or maintaining the closure of a second filter canister flushing valve (CPV2), and commanding the opening of a filter canister vent valve (CVV) to draw atmosphere across the fuel vapor storage filter canister to desorb the adsorbed fuel vapor. Depending on the engine operating conditions, the desorbed fuel vapor may be transported through a first check valve CV1 (e.g., 153) or a second check valve CV2 (e.g., 170), wherein the transport of desorbed fuel vapor through CV1 is interrupted in response to an indication that CV1 is latched closed, and wherein the transport of desorbed fuel vapor through CV2 is interrupted in response to an indication that CV2 is latched substantially closed.

[0176] Please refer to the descriptions in this article and Figures 1 to 2 The system described herein is method 900, but it should be understood that similar methods can be applied to other systems without departing from the scope of this disclosure. Method 900 can be executed by a controller, such as... Figure 1the controller 166 in FIG. 1, and can be stored in non-transitory memory at the controller as executable instructions. Instructions for performing the method 900 and the remaining methods included herein can be executed by the controller based on instructions stored on memory of the controller in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to Figures 1 to 2 The controller can employ fuel system and evaporative emission system actuators, such as CPV1 (e.g., 158), CPV2 (e.g., 165), canister vent valve (CVV) (e.g., 172), etc., in accordance with the methods described below.

[0177] The method 900 begins at 905 and can include indicating whether a request for a fuel vapor canister purge operation has been indicated during a vehicle drive cycle. The request for the fuel vapor canister purge operation can be requested in response to conditions being satisfied for the canister purge operation. For example, conditions satisfied for the canister purge operation can include an indication that an amount of fuel vapor stored in a fuel vapor canister (e.g., 104) is greater than a predetermined threshold amount, an estimate or measurement of a temperature of an emission control device, such as a catalyst, is above a predetermined temperature associated with operation of the catalyst (commonly referred to as light-off temperature), etc.

[0178] If a request for a canister purge event has not been indicated at 905, the method 900 can proceed to 910. At 910, the method 900 can include maintaining vehicle operating conditions. For example, the state of evaporative emission system actuators (e.g., CPV1, CPV2, CVV), fuel system actuators (e.g., fuel injectors, etc.), engine operating conditions (air-fuel ratio, spark timing, etc.) can be maintained.

[0179] Returning to 905, if a canister purge event request is indicated, method 900 can proceed to 915. At 915, method 900 can include indicating whether the vehicle engine is operating in a boosted condition. For example, it can be determined whether manifold air pressure (MAP) is greater than barometric pressure (BP), where the engine is operating with combustion air and fuel. Such a determination can be indicated via a pressure sensor (e.g., 115) (e.g., a MAP sensor) located in the intake manifold and a dedicated barometric pressure sensor (e.g., 119). In other examples, barometric pressure can be indicated via any conventional means. If at 915 it is indicated that the vehicle engine is operating in a boosted condition, method 900 can proceed to 920. At 920, method 900 can include indicating whether conditions for a boosted purge are satisfied. For example, conditions for a boosted purge satisfaction can include an indication that MAP is greater than BP by a predetermined threshold, and in some examples can further include that MAP is greater than BP by the predetermined threshold for a predetermined duration. If at 920 the conditions for a boosted purge are not satisfied, method 900 can proceed to 925 and can include maintaining vehicle operating conditions. Similar to that described above with respect to step 910, maintaining vehicle operating conditions at 925 can include maintaining the state of evaporative emission system actuators (e.g., CPV1, CPV2, CVV), fuel system actuators (e.g., fuel injectors, etc.), engine operating conditions (air-fuel ratio, spark timing, etc.).

[0180] If at 920 it is indicated that the conditions for a boosted purge are satisfied, method 900 can proceed to 930. At 930, method 900 can include indicating whether CV2 (e.g., 170) has previously been indicated to be stuck closed. For example, if the dual test monitoring described above with respect to method 700 indicates that CV2 is stuck closed, method 900 can proceed to 935 and can include aborting the boosted purge operation. More specifically, a stuck closed CV2 can prevent vacuum from the injector system (e.g., 140) from reaching the fuel vapor canister in the boosted condition. Thus, in response to an indication of a stuck closed CV2, purging the fuel vapor canister in the boosted condition can appear ineffective. Accordingly, the purge operation can be aborted at 935. Method 900 can then proceed to 940 and can include updating the fuel vapor canister purge operation status. For example, it can be indicated that a canister purge request was indicated and conditions for a boosted purge operation were satisfied, but the purge operation was aborted due to a stuck closed CV2. With the boosted purge operation aborted, method 900 can thus return to the beginning of method 900.

[0181] Returning to step 930, if the condition indicating that the purge operation under boosted conditions is satisfied and CV2 is not indicated to be stuck closed, the method 900 can proceed to 945. At 945, the method 900 can include commanding CPV1 to open (and maintaining or commanding CPV2 to close), and commanding CVV to open or maintain open. Proceeding to step 950, the method 900 can include purging the contents of the fuel vapor filter canister to the engine intake. More specifically, by commanding CPV1 to open and commanding CVV to open or maintain open, vacuum from the injectors (e.g., 140) under boosted conditions can be carried to the fuel vapor filter canister (e.g., 104), thereby drawing atmospheric air through the vent (e.g., 136) and through the fuel vapor filter canister. By drawing atmospheric air across the fuel vapor filter canister, stored fuel vapor can thus be desorbed and carried to the injectors. As discussed above with respect to Figure 1 the purge operation, upon entering the injectors, the air and fuel vapor can be drawn from the injectors via the outlet port (e.g., 146) and drawn into the intake pipe 118 at a location upstream of the compressor (e.g., 126). Operation of the engine, and in some examples the compressor, can then draw the air and fuel vapor through the compressor and through the charge air cooler (e.g., 156) for delivery to the intake manifold (e.g., 116) of the engine.

[0182] In some examples, purging the contents of the fuel vapor filter canister to the engine intake can include purging until the amount of stored fuel vapor in the canister is below a predetermined threshold canister load. For example, during the purge, the known vapor amount / concentration can be used to determine the amount of fuel vapor stored in the canister, and then later during the purge operation (when the canister is sufficiently purged or empty), the known vapor amount / concentration can be used to estimate the load state of the fuel vapor canister. More specifically, one or more exhaust oxygen sensors (e.g., 125) can be located in the engine exhaust to provide an estimate of the canister load (i.e., the amount of fuel vapor stored in the canister). The exhaust sensor can be any suitable sensor for providing an indication of the exhaust air-fuel ratio, such as a linear oxygen sensor or UEGO (universal or wide-range exhaust gas oxygen), a dual-state oxygen sensor or EGO, a HEGO (heated EGO), a NOx, HC, or CO sensor. Based on the canister load, and further based on the engine operating conditions, such as the engine speed-load conditions, the purge flow rate can be determined. In one example, purging the canister can include indicating the air-fuel ratio via, for example, a proportional plus integral feedback controller coupled to a dual-state exhaust oxygen sensor, and generating a base fuel command in response to the air-fuel indication and the measured of the induced air flow. To compensate for the purging vapor, the reference air-fuel ratio associated with engine operation without purging can be subtracted from the air-fuel ratio indication, and the resulting error signal (compensation factor) generated. Thus, the compensation factor can represent a known value directly related to the fuel vapor concentration, and can be subtracted from the base fuel command to correct for the induction of fuel vapor.

[0183] As discussed above with respect to Figure 1 In other examples, one or more oxygen sensors can be located in the engine intake, or coupled to the canister (e.g., 104) (e.g., downstream of the canister) to provide an estimate of the canister load. In other examples, one or more temperature sensors (e.g., 157) can be coupled to the canister (e.g., 104) and / or within the canister (e.g., 104). As the fuel vapor is desorbed by the adsorbent in the canister, the temperature change in the canister can be monitored, such that the canister load can be estimated based on the temperature change. For example, a temperature drop during desorption of the fuel vapor can be used to estimate the canister load.

[0184] Accordingly, proceeding to 955, the method 900 can include indicating whether the purge event is complete. For example, the purge event can be complete when the canister load reaches a predetermined threshold canister load. The predetermined threshold canister load can include a canister load of 10% or less of full fuel vapor. If the canister purge is indicated as not complete at 955, the method 900 can return to 950 and can include continuing to purge the contents of the canister to the engine intake. However, if the purge event is indicated as complete at 955, the method 900 can proceed to 960. At 960, the method 900 can include commanding the CPV1 to close. By commanding the CPV1 to close, the purge operation can be terminated as the fuel vapor canister can be sealed from the injectors and the engine intake.

[0185] Proceeding to 965, the method 900 can include updating the canister load status in response to the most recent purge event, and updating the canister purge schedule. For example, the canister load status can be updated at the controller and the purge schedule updated to reflect the load status of the fuel vapor canister. The method 900 can then end.

[0186] Returning to 915, if a canister purge request is indicated, but the vehicle is not operating in a boosted condition, the method 900 can proceed to 970. At 970, the method 900 can include indicating whether the vehicle is operating with the engine in a natural intake condition in which air and fuel are combusted. For example, it can be determined whether, for example, the MAP is less than the BP. As discussed above, such a determination can be indicated via a pressure sensor (e.g., MAP sensor) located in the intake manifold (e.g., 116) and a dedicated barometric pressure sensor (e.g., 119). In other examples, barometric pressure can be indicated via any conventional means. If the vehicle engine is indicated as operating with the engine in a natural intake condition in which air and fuel are combusted at 970, the method 900 can proceed to 975. At 975, the method 900 can include indicating whether conditions for a natural intake purge are satisfied. For example, conditions for a natural intake purge to be satisfied can include an indication that the MAP is less than the BP by a predetermined threshold, and in some examples can further include that the MAP is less than the BP by the predetermined threshold for a predetermined duration. If the conditions for a natural intake purge are not satisfied at 975, the method 900 can proceed to 980 and can include maintaining the vehicle regime. Similar to that described above, maintaining the vehicle regime at 980 can include maintaining the state of the evaporative emission system actuators (e.g., CPV1, CPV2, CVV), the fuel system actuators (e.g., fuel injectors, etc.), the engine operating state (air-fuel ratio, spark timing, etc.).

[0187] Returning to 975, if the condition indicating that the purge operation under natural intake conditions is satisfied, the method 900 can proceed to 985. At 985, the method 900 can include indicating whether CV1 (e.g., 153) has previously been indicated to be stuck closed. For example, if the double test monitoring described above with respect to the method 700 indicates that CV1 is stuck closed, the method 900 can proceed to 990 and can include aborting the purge operation under natural intake conditions. More specifically, a CV1 stuck closed can prevent a significant vacuum from the engine air intake from reaching the fuel vapor canister. Thus, in response to an indication of a CV1 stuck closed, purging the fuel vapor canister under natural intake conditions can appear to be ineffective. Accordingly, the purge operation can be aborted at 990. The method 900 can then proceed to 995 and can include updating the fuel vapor canister purge operation status. For example, it can be indicated that a canister purge request was indicated and the condition for a purge operation under natural intake was satisfied, but the purge operation was aborted because of a CV1 stuck closed. With the natural intake purge operation aborted, the method 900 can thus return to the beginning of the method 900.

[0188] Returning to step 985, if the condition indicating that the purge operation under natural intake conditions is satisfied and CV1 is not indicated to be stuck closed, the method 900 can proceed to 945. In response to the method 900 reaching step 945 after indicating that CV1 is not stuck closed, steps 945 through 965 can proceed exactly as described above. Thus, to avoid redundancy, steps 945 through 965 will not be repeated here.

[0189] Now turning to Figure 10 , a method for using a purge valve as described above with respect to Figure 7An example timeline 1000 of a dual test monitoring method performing an evaporative emission test diagnostic procedure is discussed. The timeline 1000 includes a curve 1005 indicating whether an on event has been indicated over time. The timeline 1000 further includes a curve 1010 indicating a state of an electric supercharger (e.g., 155) over time. In this example, the electric supercharger can be on or off. The timeline 1000 further includes a curve 1015 indicating a state of an engine (e.g., 112) over time. The engine can be off, or can be operating with fuel added to combust air and fuel, or can be operating without fuel added, such as via a motor (e.g., 220) to spin or rotate the engine without providing fuel or a spark to the engine cylinders. The timeline 1000 further includes a curve 1020 indicating manifold air pressure (MAP) relative to barometric pressure (BP), where BP is represented by line 1021. The timeline 1000 further includes a curve 1025 indicating whether a first canister purge valve (CPV1) (e.g., 158) is open or closed over time, a curve 1030 indicating whether a second canister purge valve (CPV2) (e.g., 165) is open or closed over time, and a curve 1035 indicating whether a canister vent valve (CVV) (e.g., 172) is open or closed over time. The timeline 1000 further includes a curve 1040 indicating pressure (atmospheric pressure, abbreviated Atm, and negative pressure relative to atmospheric pressure (vacuum), abbreviated Vac) in the evaporative emission system (e.g., 154) and fuel system (e.g., 106) over time, as indicated by, for example, a fuel tank pressure sensor (FTPT) (e.g., 107). Line 1041 represents a predetermined threshold vacuum, which if reached during the evaporative emission test diagnostic procedure, can indicate that there are no significant undesirable evaporative emissions. Line 1042 represents a predetermined pressure rise threshold, which if reached after reaching the predetermined threshold vacuum and after sealing the fuel system and evaporative emission system from the engine intake and atmosphere, can indicate that there are non-significant undesirable evaporative emissions.

[0190] Timeline 1000 further includes a curve 1045 indicating whether there is (yes) or is not (no) an indication that the first check valve (CV1) (e.g., 153) is stuck closed over time, and a curve 1050 indicating whether there is (yes) or is not (no) an indication that the second check valve (CV2) (e.g., 170) is stuck closed over time. Timeline 1000 can further include a curve 1055 indicating whether there is a significant undesirable evaporative emission in the evaporative emission system and / or the fuel system over time. For example, a significant undesirable evaporative emission can correspond to a predetermined orifice diameter of 0.04” or greater. Timeline 1000 further includes a curve 1060 indicating whether there is a non-significant undesirable evaporative emission in the evaporative emission system and / or the fuel system over time. For example, a non-significant undesirable evaporative emission can correspond to a predetermined orifice diameter that is less than the predetermined orifice diameter corresponding to a significant undesirable evaporative emission.

[0191] At time to, the vehicle is not in operation, as indicated by curve 1005. Accordingly, the MAP is indicated at the BP, as indicated by curve 1020, since the engine is not in operation. CPV1 and CPV2 are closed, as indicated by curves 1025 and 1030, respectively, and CVV is open, as indicated by curve 1035. With CVV open, the fuel system and the evaporative emissions are not sealed from the atmosphere, and thus the pressure sensor (FTPT) (e.g., 107) located between the fuel system and the evaporative emission system indicates atmospheric pressure, as indicated by curve 1020. CV1 (e.g., 153) is not indicated as stuck closed, as indicated by curve 1045, and CV2 (e.g., 170) is not indicated as stuck closed, as indicated by curve 1050. Furthermore, a significant undesirable evaporative emission is not indicated, as indicated by curve 1055, and a non-significant undesirable evaporative emission is not indicated, as indicated by curve 1060.

[0192] At time ti, it can be appreciated that the conditions indicating that the engine off test for undesirable evaporative emissions under boost is satisfied (see step 310 of method 300) are met. Accordingly, the electrically powered supercharger (e.g., 155) is activated or actuated, the CVV is commanded to close, and CPV2 is commanded to open. CPV1 is maintained closed. With the electrically powered supercharger activated, the pressure in the intake manifold becomes positive with respect to atmospheric pressure between times ti and t2, as indicated by curve 1020. The positive pressure thus results in a negative pressure with respect to atmospheric pressure between times ti and t2 in the fuel system and the evaporative emission system as a result of the injector system (e.g., 141), as indicated by curve 1040.

[0193] At time t2, the pressure in the fuel system and evaporative emission system reaches a predetermined threshold vacuum, represented by line 1041. Therefore, because the predetermined threshold vacuum has been reached, no significant undesirable evaporative emissions are indicated, as shown by curve 1055, and CV2 is not indicated to be stuck shut, as shown by curve 1050. As discussed above, these results can be stored at the controller (e.g., 166). However, as described in detail above, although CV2 is not indicated to be stuck shut, it may not be definitively determined that CV1 is not stuck shut.

[0194] At time t2, in response to reaching a predetermined threshold vacuum, CPV2 is commanded to shut down, while CPV1 and CVV remain shut down. This allows the fuel system and evaporative emission system to be sealed off from the engine intake and the atmosphere. The pressure in the fuel system and evaporative emission system can therefore be monitored for a predetermined duration to indicate the presence or absence of insignificant, undesirable evaporative emissions. Therefore, between times t2 and t3, pressure relief in the fuel system and evaporative emission system is monitored, as indicated by curve 1040. By time t3, the pressure relief indicates that the pressure relief remains below a predetermined pressure rise threshold, represented by line 1042. This indicates that there are no insignificant, undesirable evaporative emissions in the fuel system and evaporative emission system.

[0195] At time t3, the CVV is commanded to open. With the CVV open and CPV1 and CPV2 closed, the pressure in the fuel system and evaporative emission system returns to atmospheric pressure between times t3 and t4, as shown by curve 1040.

[0196] At time t4, it can be understood that the conditions for conducting an evaporative emissions test under naturally aspirated conditions are met, where the engine operates without fuel, as described above. Figure 5 Discussion at the venue. Figure 5 Step 510 details the conditions required to perform this test. It is understood that, in order to meet these conditions, the threshold duration has not yet been indicated since the previous test under boost operation conducted between times t1 and t3. This threshold duration was discussed above at, for example, steps 726 and 756 of method 700. Since the conditions for conducting a diagnostic test of unfueled engine spin evaporative emissions are indicated at time t4, the engine is controlled to spin in the default or forward direction without providing fuel and spark, as indicated by curve 1015. Furthermore, CPV2 is commanded to open, while CVV is commanded to close. Therefore, between times t4 and t5, with the engine spinning without fuel, the pressure in the intake manifold decreases to below atmospheric pressure or atmospheric pressure, as indicated by curve 1020.

[0197] In the event that the command to open CPV2, the command to close CVV, and the engine spinning with no fuel being added, if CV1 is not stuck closed, then a pressure reduction in the fuel system and the evaporative emission system below atmospheric pressure can be expected, as no significant undesirable evaporative emissions are indicated between times ti and t2 of the example timeline 1000. However, a pressure reduction in the fuel system and the evaporative emission system is not indicated, as shown by curve 1040. Thus, at time t5, CV1 is indicated to be stuck closed. In other words, the example timeline 1000 can thus represent a result C, as described above with respect to the lookup table 800 shown above at Figure 8 time t5, the results from the evaporative emission test diagnosis conducted under boost (engine off condition) and the results from the test conducted under natural intake (engine spinning with no fuel added) can be analyzed by the controller and interpreted via, for example, a lookup table stored at the controller, such as the lookup table 800 shown above at Figure 8 time t5, CV1 is indicated to be stuck closed, the MIL can be illuminated on the vehicle dashboard, alerting the vehicle driver of the stuck closed CV1. Further, at time t5, in response to the completion of the dual test monitoring, CPV2 can be commanded closed and CVV can be commanded open. Thus, with CVV open, the pressure in the fuel system and the evaporative emission system returns to / maintains atmospheric pressure between times t5 and t6, as indicated by curve 1040.

[0198] Turning now to Figure 11indicating whether a fuel vapor canister purge request has been indicated over time. Timeline 1100 further includes curve 1110 indicating manifold air pressure (MAP) relative to barometric pressure (BP) over time, where BP is represented by line 1111. Timeline 1100 further includes curve 1115 indicating the open or closed state of a first canister purge valve (CPV1) (e.g., 158) over time, curve 1120 indicating the open or closed state of a second canister purge valve (CPV2) (e.g., 165) over time, and curve 1125 indicating the open or closed state of a canister vent valve (CVV) (e.g., 172) over time. Timeline 1100 further includes curve 1130 indicating whether a first check valve (CV1) (e.g., 153) is stuck closed over time, and curve 1135 indicating whether a second check valve (CV2) (e.g., 170) is stuck closed over time. Timeline 1100 further includes curve 1140 indicating a canister loading state of a fuel vapor canister (e.g., 104) over time. Line 1141 represents a threshold canister loading state, where if reached during a purge event, the purge event can be indicated as complete.

[0199] At time to, it can be understood that the vehicle is in operation and the engine is burning air and fuel, and no request to purge the fuel vapor canister has been indicated. The MAP is negative relative to the BP, as indicated by curve 1110. In other words, it can be understood that the engine is operating under natural aspiration as the engine is burning air and fuel. As no canister purge operation is taking place, it is indicated that CPV1 is closed, as shown by curve 1115, that CVV is open, as shown by curve 1125, and that CPV2 is closed, as shown by curve 1120. With CPV1 and CPV2 closed, the fuel system (e.g., 106) and the evaporative emission system (e.g., 154) can be sealed from the engine intake, as discussed above. With CVV open, the fuel system and the evaporative emission system can be fluidly coupled in communication to the atmosphere. As CVV is open, fuel vapor (e.g., run loss fuel vapor) generated in the fuel tank during vehicle operation can be directed to the fuel vapor canister for storage before exiting to the atmosphere. Thus, between times to and ti, despite the engine being in operation, the canister loading state is indicated to increase slightly. As discussed above, in some examples, a temperature sensor (e.g., 157) located within the fuel vapor canister can be used to infer the canister loading state.

[0200] At time ti, a purge request is indicated. In some examples, the request for purge can include a canister loading state above a threshold level (not shown), a vacuum level in the intake manifold greater than a threshold vacuum level (not shown), etc. However, even though a purge request is indicated at time ti, because CVi was previously indicated to be stuck closed, CPVi can remain closed and CVv can remain open. In other words, a purge operation under natural intake can be prevented (e.g., aborted). More specifically, CVi can have been indicated to be stuck closed in response to a dual test monitoring of the fuel system and evaporative emission system, such as the dual test monitoring described in detail above with respect to Figure 7 The dual test monitoring described in detail above. Because CVi is indicated to be stuck closed, a purge operation can be prevented because a stuck closed CVi can render a purge operation ineffective. Thus, between times ti and t2, the vehicle operating conditions are maintained without a purge operation.

[0201] At time t2, the MAP is indicated to be equal to BP, and between times t2 and t3, the MAP becomes greater than BP. Thus, it can be appreciated that between times t2 and t3, the engine is operating under a boosted condition, where the engine is operating to combust air and fuel. At time t3, a condition is indicated that is satisfied for a purge operation under a boosted condition where the engine is operating to combust air and fuel. For example, a condition that can be satisfied for a purge operation under boost can include the MAP being greater than the BP by a predetermined threshold (not shown) for a predetermined duration (not shown). A condition that can be satisfied for a purge operation under boost can further include, for example, a canister loading being above a predetermined threshold canister loading (not shown). A condition that can be satisfied for a purge operation under boost can further include an indication that CV2 is not stuck closed. Thus, at time t3, CPVi is commanded to open, indicated by curve 1115. As discussed above, by commanding CPVi to open at time t3, a vacuum from the injectors (e.g., 140) during the boosted condition can be applied to the fuel vapor canister. By applying a vacuum to the fuel vapor canister with CPVi open and CVv open, atmospheric air can be drawn across the fuel vapor canister, thus desorbing fuel vapor stored in the fuel vapor canister.

[0202] Between times t3 and t4, a canister loading state is indicated to decrease. The canister loading state can be indicated via, for example, any of the methods described above with respect to Figure 9 At time t4, the canister loading state is indicated to reach a threshold canister loading state, represented by line 1141. Thus, the fuel vapor canister can be indicated to be substantially free of fuel vapor. In other words, the fuel vapor canister can be indicated to be purged. Because the canister is indicated to be purged, CPVi is commanded to close at time t4, and the purge request is terminated.

[0203] Between times t4 and t5, the vehicle remains in operation and the MAP fluctuates, at time t5 equals BP. Between times t5 and t6, the engine again operates in a natural aspiration condition, indicated by curve 1110.

[0204] In this manner, the evaporative emission system can be diagnosed for the presence or absence of significant undesirable evaporative emissions, non-significant undesirable evaporative emissions, and whether CV1 (e.g., 153) and CV2 (e.g., 170) are functioning as desired. Such indications can allow for mitigating actions to be taken by the vehicle controller to reduce the release of undesirable evaporative emissions into the atmosphere, such as by alerting the vehicle driver to service the vehicle. Such indications can additionally allow for filter canister purge operations to be performed in a timely manner, such that filter canister purge operations are not performed in situations where the purge operations can be ineffective. For example, if CV1 is stuck closed, then a purge can not be performed in a natural aspiration condition, as described above.

[0205] A technical effect is the recognition that, for a hybrid vehicle having limited engine run time (where limited engine run time refers to conditions where the engine is burning air and fuel), the dual test monitoring as discussed above at Figure 7

[0206] Additionally, a further technical effect is the recognition that an electric supercharger can be utilized, in conditions where the engine is not burning air and fuel, in order to perform evaporative emission test diagnostics on the vehicle fuel system and evaporative emission system. As discussed, the ability to perform such testing increases the opportunity to detect the source of undesirable evaporative emissions in vehicles having limited engine run time, such as hybrid vehicles.

[0207] The systems described are in conjunction with and the systems described herein and with respect to Figures 1 to 2 The systems described are in conjunction with and the systems described herein and with respect to Figures 3 to 7 and Figure 9 ​The illustrated methods can implement one or more systems and one or more methods. In one example, a method includes: supplying air from an electric compressor to an engine propelling a vehicle under predetermined conditions; evacuating a fuel system and an evaporative emissions system of the vehicle to a threshold vacuum by activating the electric compressor when the engine is off; and indicating a presence or absence of non-significant undesirable evaporative emissions based on a pressure rise in the fuel system and the evaporative emissions system after the threshold vacuum is reached. In a first example of the method, the method further includes wherein evacuating the fuel system and the evaporative emissions system further comprises fluidly coupling the fuel system and the evaporative emissions system to an injector system of the vehicle, wherein the injectors function to evacuate the fuel system and the evaporative emissions system when the electric compressor is activated. In a second example of the method, the method further includes sealing the fuel system and the evaporative emissions system from atmosphere and the engine in response to reaching the threshold vacuum in order to indicate the presence or absence of non-significant undesirable evaporative emissions based on the pressure rise in the fuel system and the evaporative emissions system. A third example of the method optionally includes any one or more or each of the first and second examples, and further includes wherein indicating the presence or absence of non-significant undesirable evaporative emissions based on the pressure rise in the fuel system and the evaporative emissions system further comprises: indicating a presence of non-significant undesirable evaporative emissions in response to the pressure rise being greater than a predetermined pressure rise threshold or in response to the pressure rise being greater than a predetermined pressure rise rate threshold for a predetermined duration. A fourth example of the method optionally includes any one or more or each of the first through third examples, and further includes wherein indicating an absence of significant undesirable evaporative emissions in the fuel system and the evaporative emissions system in response to reaching the threshold vacuum during evacuating the fuel system and the evaporative emissions system via activating the electric compressor; and indicating that a second check valve located upstream of the injector system is functioning as needed. A fifth example of the method optionally includes any one or more or each of the first through fourth examples, and further includes wherein indicating an absence of significant undesirable evaporative emissions in the fuel system and the evaporative emissions system in response to reaching the threshold vacuum during evacuating the fuel system and the evaporative emissions system via activating the electric compressor; and indicating that a first check valve located upstream of an intake of the engine is functioning as needed in response to reaching the threshold vacuum during evacuating the fuel system and the evaporative emissions system under negative pressure conditions in the intake of the engine with the electric compressor being off.A sixth example of the method optionally includes any one or more or each of the first through fifth examples, and further includes indicating a presence of significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system in response to not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, and further in response to not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system in the condition of negative pressure in the intake of the engine. A seventh example of the method optionally includes any one or more or each of the first through sixth examples, and further includes indicating that the first check valve is stuck closed and indicating an absence of significant undesirable evaporative emissions in the fuel system and the evaporative emissions system in response to reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, but not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system in the condition of negative pressure in the intake of the engine; and indicating that the second check valve is stuck closed and indicating an absence of significant undesirable evaporative emissions in the fuel system and the evaporative emissions system in response to not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, but reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system in the condition of negative pressure in the intake of the engine. An eighth example optionally includes any one or more or each of the first through seventh examples, and further includes wherein evacuating the fuel system and the evaporative emissions system in the condition of negative pressure in the intake of the engine includes the engine being in a condition of combusting air and fuel, or the engine spinning without fuel to create the negative pressure in the intake of the engine. A ninth example optionally includes any one or more or each of the first through eighth examples, and further includes wherein evacuating the fuel system and the evaporative emissions system via activation of the electric compressor further includes pumping air and fuel vapors through an entirety of a fuel vapor canister located in the evaporative emissions system from a fuel tank located in the fuel system prior to the air and fuel vapors being delivered to the engine, the fuel vapor canister being configured to adsorb fuel vapors from the fuel tank; and wherein evacuating the fuel system and the evaporative emissions system in the condition of negative pressure in the intake of the engine includes pumping air and fuel vapors through the entirety of the fuel vapor canister from the fuel tank, wherein the negative pressure in the intake is created via spinning the engine without fuel.

[0208] Another example of a method includes evacuating a fuel system and an evaporative emissions system of a vehicle including an engine via a first check valve in a first condition, the first condition including a negative pressure in an air intake of the engine relative to atmospheric pressure; evacuating the fuel system and the evaporative emissions system via a second check valve in a second condition, the second condition including activating an electrically powered compressor configured to supply air to the engine under predetermined conditions, wherein the first condition and the second condition do not occur in a particular order and wherein the first condition and the second condition occur within a predetermined duration of each other; indicating a presence or absence of significant undesirable evaporative emissions in the fuel system and / or the evaporative emissions system based on a vacuum level in the fuel system and evaporative emissions system relative to a threshold vacuum reached during evacuation of the fuel system and the evaporative emissions system under one or more of the first condition and the second condition, and indicating whether one of the first check valve or the second check valve is stuck closed; and indicating a presence or absence of non-significant undesirable evaporative emissions in the fuel system and / or the evaporative emissions system under either or both of the first condition and the second condition based on a pressure rise in the fuel system and evaporative emissions system in response to reaching the threshold vacuum under either or both of the first condition and / or the second condition and the fuel system and evaporative emissions system being sealed from atmospheric and the engine. In the first example of the method, the method further includes wherein evacuating the fuel system and the evaporative emissions system of the vehicle in the first condition occurs via the engine combusting air and fuel, or via the engine spinning without fuel, wherein the engine combusting air and fuel and / or wherein spinning the engine without fuel results in a negative pressure in an air intake of the engine relative to atmospheric pressure. The second example of the method optionally includes the first example, and further includes wherein evacuating the fuel system and the evaporative emissions system includes carrying fuel vapor from the fuel system through an entirety of a fuel vapor canister located in the evaporative emissions system and configured to store fuel vapor from the fuel system in the first condition of the engine spinning without fuel, or in the second condition of the electrically powered compressor being activated; and wherein evacuating the fuel system and the evaporative emissions system includes carrying fuel vapor from the fuel system through a portion of the fuel vapor canister in the first condition of the engine combusting air and fuel.A third example of the method optionally includes any one or more or each of the first and second examples, and further includes purging fuel vapor stored in the fuel vapor canister to the engine to draw atmospheric air across the fuel vapor storage canister to desorb fuel vapor in selected engine operating conditions by fluidly coupling the fuel vapor canister to the engine and by fluidly coupling a vent line from the fuel vapor canister to atmosphere; wherein desorbed fuel vapor is carried through the first check valve or the second check valve depending on the selected engine operating conditions; wherein carrying desorbed fuel vapor through the first check valve is interrupted in response to an indication that the first check valve is stuck closed; and wherein carrying desorbed fuel vapor through the second check valve is interrupted in response to an indication that the second check valve is stuck closed. A fourth example of the method optionally includes any one or more or each of the first through third examples, and further includes indicating that the second check valve is stuck closed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum not being reached during the second condition but being reached during the first condition; indicating that the first check valve is stuck closed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum not being reached during the first condition but being reached during the second condition; indicating that both the first check valve and the second check valve are functioning as needed and indicating that there is no significant undesirable evaporative emissions in response to the threshold vacuum being reached during both the first condition and the second condition; and indicating that there is significant undesirable evaporative emissions in response to the threshold vacuum not being reached during both the first condition and the second condition. A fifth example of the method optionally includes any one or more or each of the first through fourth examples, and further includes wherein indicating the presence or absence of non-significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system further includes indicating the absence of non-significant undesirable evaporative emissions in response to the pressure rise in the fuel system and evaporative emissions system remaining below a pressure rise threshold or in the case of a pressure rise rate in the fuel system and evaporative emissions system remaining below a pressure rise rate threshold for a predetermined duration. A sixth example of the method optionally includes any one or more or each of the first through fifth examples, and further includes wherein evacuating the fuel system and the evaporative emissions system via the second check valve in the second condition involves coupling the fuel system and the evaporative emissions system to the engine via a hole having a reduced inlet pressure by Venturi effect.

[0209] A system for a vehicle includes an engine including an air intake; a motor configured to spin the engine without fuel; a fuel system including a fuel tank fluidly coupled to an evaporative emissions system including a fuel vapor canister; a canister vent valve in a vent line coupling the fuel vapor canister to atmosphere; a first canister purge valve in a purge line from the fuel vapor canister; a second canister purge valve selectively fluidly coupled to the purge line via a first conduit and to the vent line via a second conduit; a first check valve in a conduit upstream of an air intake of the engine and downstream of the first and second canister purge valves; a second check valve in the purge line downstream of the conduit downstream of the first and second canister purge valves and upstream of the air intake of the engine; an eductor system downstream of the second check valve; an electric compressor in an air intake upstream of an air intake throttle and configured to supply air to the engine; a fuel tank pressure sensor between the fuel tank and the fuel vapor canister; and a controller storing instructions in non-transitory memory that, when executed, cause the controller to: in a first condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the first check valve by spinning the engine without fuel via the motor to create a vacuum in the air intake of the engine to evacuate the fuel system and the evaporative emissions system; in a second condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the second check valve via the eductor system with the electric compressor activated; indicate a presence or absence of significant undesirable evaporative emissions and whether the first and second check valves are functioning as needed depending on whether a threshold vacuum is reached during evacuation of the fuel system and the evaporative emissions system in both the first and second conditions, wherein the threshold vacuum is indicated via the fuel tank pressure sensor.And based on a pressure rise in either or both of the first condition and / or the second condition as indicated via the fuel tank pressure sensor in the fuel system and the evaporative emissions system after the threshold vacuum is reached and after the fuel system and the evaporative emissions system are sealed from the air intake of the engine and atmosphere after the threshold vacuum is reached, indicating the presence or absence of non-significant undesirable evaporative emissions in the fuel system and the evaporative emissions system. In a first example of the system, the system further includes where the controller stores additional instructions to indicate that both the first check valve and the second check valve are functioning as needed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum being reached in both the first condition and the second condition; that the first check valve is stuck closed but the second check valve is functioning as needed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum being reached in the second condition but not the first condition; that the second check valve is stuck closed but the first check valve is functioning as needed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum being reached in the first condition but not the second condition; and that there is significant undesirable evaporative emissions in response to the threshold vacuum not being reached during either the first condition or the second condition. A second example of the system optionally includes the first example, and further includes where the controller stores additional instructions to, in either or both of the first condition and / or the second condition, in response to the threshold vacuum being reached, seal the fuel system and the evaporative emissions system by commanding the second canister purge valve closed and commanding or maintaining the canister vent valve and the first canister purge valve closed; monitor the pressure in the fuel system and the evaporative emissions system via the fuel tank pressure sensor; and in a predetermined duration, in response to the pressure in the fuel system and the evaporative emissions system remaining below a pressure rise threshold, or in response to a rate of pressure rise in the fuel system and the evaporative emissions system remaining below a pressure rise rate threshold, indicate that there is non-significant undesirable evaporative emissions.

[0210] It should be noted that the example control and estimation routines included herein can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in non-transitory memory and can be executed by control systems comprising controllers including microprocessors, microcontrollers, programmable logic devices, and / or other processing devices. The specific routines described herein can represent one or more of any number of processing strategies such as event-driven, interrupt-driven, multi-tasking, multi-threading, and so on. As such, various acts, operations, and / or functions illustrated can be performed in the manner shown, in parallel, or in some cases omitted. Likewise, the order of processing is not necessarily restricted to that shown unless specifically stated. The examples described herein are used by way of example to illustrate the disclosed embodiments and should not be construed in a limiting sense. One skilled in the art will recognize that the examples set forth herein were provided to enable those skilled in the art to make and use like-based implementations and merely set forth examples of the various operational capabilities of the systems, apparatuses, and / or devices. Further, to the extent that the methods, techniques, and / or processes described herein can be implemented, at least in part, with the aid of a computer, the disclosed embodiments do not rely on use of a computer for their implementation, and are implemented, at least in part, by human technicians.

[0211] It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, opposed 4 cylinder, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, and other features, functions, and / or properties disclosed herein.

[0212] The following claims particularly point out certain combinations and sub-combinations that are regarded as novel and non-obvious. These claims can refer to "a" or "an" element, or to "first" or "second" elements or the equivalent thereof. Such claims should be understood as including one or several such elements, whether or not further iterations of the elements are also claimed. Other elements, both those that have been described and those that have not, can be claimed in any combination or sub-combination, by amendment of the present claims or by presentation of additional claims, by virtue of the disclosure. The claims, whether broader, narrower, equal, or different, are also regarded as within the subject matter of the present disclosure.

[0213] According to the present invention, there is provided a method having: supplying air from an electric compressor to an engine propelling a vehicle under predetermined conditions; evacuating a fuel system and an evaporative emission system of the vehicle to a threshold vacuum by activating the electric compressor when the engine is off; and indicating the presence or absence of a non-negligible undesirable evaporative emission based on a pressure rise in the fuel system and the evaporative emission system after the threshold vacuum is reached.

[0214] According to embodiments, the above invention is further characterized by evacuating the fuel system and the evaporative emissions system via activation of the electric compressor further comprises fluidly coupling the fuel system and the evaporative emissions system to an injector system of the vehicle, wherein the injectors function to evacuate the fuel system and the evaporative emissions system upon activation of the electric compressor.

[0215] According to embodiments, in response to reaching the threshold vacuum, sealing the fuel system and the evaporative emissions system from atmosphere and the engine so as to indicate the presence or absence of a non-significant undesirable evaporative emission based on the pressure rise in the fuel system and the evaporative emissions system.

[0216] According to embodiments, the above invention is further characterized by indicating the presence or absence of a non-significant undesirable evaporative emission based on the pressure rise in the fuel system and the evaporative emissions system further comprises: indicating the presence of a non-significant undesirable evaporative emission in response to the pressure rise being greater than a predetermined pressure rise threshold, or in response to the pressure rise being greater than a predetermined pressure rise rate threshold, for a predetermined duration.

[0217] According to embodiments, in response to reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, indicating the absence of a significant undesirable evaporative emission in the fuel system and the evaporative emissions system, and indicating that a second check valve located upstream of an injector system is functioning as desired.

[0218] According to embodiments, in response to reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, and subsequently evacuating the fuel system and the evaporative emissions system in a condition of negative pressure in an air intake of the engine with the electric compressor off; indicating whether the threshold vacuum is reached during evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the air intake of the engine; and in response to reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure, indicating that a first check valve located upstream of the air intake is functioning as desired.

[0219] According to embodiments, in response to not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, and further in response to not reaching the threshold vacuum during evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the air intake of the engine, indicating the presence of a significant undesirable evaporative emission in the fuel system and / or the evaporative emissions system.

[0220] According to embodiments, in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, but not reached during evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the intake of the engine, it is indicated that the first check valve is stuck closed and that there is no significant undesirable evaporative emissions in the fuel system and the evaporative emissions system; and

[0221] In response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the intake of the engine, but not reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, it is indicated that the second check valve is stuck closed and that there is no significant undesirable evaporative emissions in the fuel system and the evaporative emissions system.

[0222] According to embodiments, the above invention is further characterized in that evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the intake of the engine comprises the engine combusting air and fuel, or the engine spinning without fuel to create the condition of negative pressure in the intake of the engine.

[0223] According to embodiments, the above invention is further characterized in that evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor further comprises, prior to the air and fuel vapors being delivered to the engine, the air and fuel vapors being drawn from a fuel tank located in the fuel system through an entirety of a fuel vapor canister located in the evaporative emissions system, the fuel vapor canister being configured to adsorb fuel vapors from the fuel tank; and wherein evacuation of the fuel system and the evaporative emissions system in a condition of negative pressure in the intake of the engine comprises the air and fuel vapors being drawn from the fuel tank through the entirety of the fuel vapor canister, wherein the negative pressure in the intake is created via the engine spinning without fuel.

[0224] According to embodiments, the present application is further characterized by evacuating a fuel system and an evaporative emissions system of a vehicle including an engine via a first check valve in a first condition including a negative pressure in an air intake of the engine relative to atmospheric pressure; evacuating the fuel system and the evaporative emissions system via a second check valve in a second condition including activating an electrically powered compressor configured to supply air to the engine under predetermined conditions, wherein the first condition and the second condition do not occur in a particular order and wherein the first condition and the second condition occur within a predetermined duration of each other; indicating a presence or absence of significant undesirable evaporative emissions in the fuel system and / or the evaporative emissions system based on a vacuum level in the fuel system and evaporative emissions system relative to a threshold vacuum reached during evacuation of the fuel system and the evaporative emissions system under one or more of the first condition and the second condition, and indicating whether one of the first check valve or the second check valve is stuck closed; and indicating a presence or absence of non-significant undesirable evaporative emissions in the fuel system and / or the evaporative emissions system under either or both of the first condition and the second condition based on a pressure rise in the fuel system and evaporative emissions system in response to reaching the threshold vacuum under either or both of the first condition and / or the second condition and the fuel system and evaporative emissions system being sealed from atmospheric and the engine.

[0225] According to embodiments, the present application is further characterized by evacuating the fuel system and the evaporative emissions system of the vehicle in the first condition via the engine combusting air and fuel, or via the engine spinning without fuel, wherein the engine combusting air and fuel and / or wherein spinning the engine without fuel results in a negative pressure in an air intake of the engine relative to atmospheric pressure.

[0226] According to embodiments, evacuating the fuel system and the evaporative emissions system includes transporting fuel vapor from the fuel system through an entirety of a fuel vapor canister located in the evaporative emissions system and configured to store fuel vapor from the fuel system in a first condition in which the engine is spinning without fuel, or in a second condition in which the electrically powered compressor is activated; and wherein evacuating the fuel system and the evaporative emissions system includes transporting fuel vapor from the fuel system through a portion of the fuel vapor canister in a first condition in which the engine is combusting air and fuel.

[0227] According to embodiments, the above invention is further characterized by purging fuel vapor stored in the fuel vapor filter canister to the engine to draw atmospheric air across the fuel vapor storage canister to desorb fuel vapor in selected engine operating conditions by fluidly coupling the fuel vapor filter canister to the engine and by fluidly coupling a vent line from the fuel vapor filter canister to atmospheric air; wherein desorbed fuel vapor is routed through the first check valve or the second check valve depending on the selected engine operating conditions; wherein routing desorbed fuel vapor through the first check valve is interrupted in response to an indication that the first check valve is stuck closed; and wherein routing desorbed fuel vapor through the second check valve is interrupted in response to an indication that the second check valve is stuck closed.

[0228] According to embodiments, the above invention is further characterized by indicating that the second check valve is stuck closed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum not being reached during the second condition but being reached during the first condition; indicating that the first check valve is stuck closed and that there is no significant undesirable evaporative emissions in response to the threshold vacuum not being reached during the first condition but being reached during the second condition; indicating that both the first check valve and the second check valve are functioning as needed and indicating that there is no significant undesirable evaporative emissions in response to the threshold vacuum being reached during both the first condition and the second condition; and indicating that there is significant undesirable evaporative emissions in response to the threshold vacuum not being reached during both the first condition and the second condition.

[0229] According to embodiments, the above invention is further characterized by indicating the presence or absence of non-significant undesirable evaporative emissions in the fuel system and / or evaporative emissions system further comprises indicating the absence of non-significant undesirable evaporative emissions in response to the pressure rise in the fuel system and evaporative emissions system remaining below a pressure rise threshold or a rate of pressure rise in the fuel system and evaporative emissions system remaining below a rate of pressure rise threshold for a predetermined duration.

[0230] According to embodiments, the above invention is further characterized by evacuating the fuel system and the evaporative emissions system via the second check valve in the second condition involves coupling the fuel system and the evaporative emissions system to the engine via an orifice having a reduced inlet pressure by Venturi effect.

[0231] According to the present invention, there is provided a system for a vehicle, the system having: an engine including an air intake; a motor configured to spin the engine without fuel; a fuel system including a fuel tank fluidly coupled to an evaporative emissions system including a fuel vapor canister; a canister vent valve in a vent line coupling the fuel vapor canister to atmosphere; a first canister purge valve in a purge line originating from the fuel vapor canister; a second canister purge valve selectively fluidly coupled to the purge line via a first conduit and selectively fluidly coupled to the vent line via a second conduit; a first check valve in a conduit upstream of an air intake of the engine and downstream of the first and second canister purge valves; a second check valve in the purge line downstream of the conduit downstream of the first and second canister purge valves and upstream of the air intake of the engine; an eductor system downstream of the second check valve; an electric compressor in an air intake upstream of an air intake throttle and configured to supply air to the engine; a fuel tank pressure sensor between the fuel tank and the fuel vapor canister; and a controller storing instructions in a non-transitory memory that, when executed, cause the controller to: in a first condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the first check valve by spinning the engine without fuel via the motor to create a vacuum in the air intake of the engine to evacuate the fuel system and the evaporative emissions system; in a second condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the second check valve via the eductor system with the electric compressor activated; indicate the presence or absence of significant undesirable evaporative emissions and whether the first and second check valves are functioning as needed as a function of whether a threshold vacuum is reached during evacuation of the fuel system and the evaporative emissions system in both the first and second conditions, wherein the threshold vacuum is indicated via the fuel tank pressure sensor.And based on a pressure rise in either or both of the first condition and / or the second condition as indicated via the fuel tank pressure sensor in the fuel system and the evaporative emissions system after reaching the threshold vacuum and after sealing the fuel system and the evaporative emissions system from the air intake of the engine and atmosphere after reaching the threshold vacuum, indicating the presence or absence of non-significant undesirable evaporative emissions in the fuel system and the evaporative emissions system.

[0232] According to embodiments, the controller stores additional instructions to indicate that the first and second check valves are functioning as needed and that there is no significant undesirable evaporative emissions in response to reaching the threshold vacuum in both the first condition and the second condition; that the first check valve is stuck closed but the second check valve is functioning as needed and that there is no significant undesirable evaporative emissions in response to reaching the threshold vacuum in the second condition but not the first condition; that the second check valve is stuck closed but the first check valve is functioning as needed and that there is no significant undesirable evaporative emissions in response to reaching the threshold vacuum in the first condition but not the second condition; and that there is significant undesirable evaporative emissions in response to not reaching the threshold vacuum during either the first condition or the second condition.

[0233] According to embodiments, the controller stores additional instructions to, in either or both of the first condition and / or the second condition, in response to reaching the threshold vacuum, seal the fuel system and the evaporative emissions system by commanding the second canister purge valve closed and commanding or maintaining the canister vent valve and the first canister purge valve closed; monitor the pressure in the fuel system and evaporative emissions system via the fuel tank pressure sensor; and in response to the pressure in the fuel system and the evaporative emissions system remaining below a pressure rise threshold, or in response to a rate of pressure rise in the fuel system and the evaporative emissions system remaining below a pressure rise rate threshold, for a predetermined duration, indicate that there is non-significant undesirable evaporative emissions.

Claims

1. A method for a vehicle, the method comprising: supplying air from an electric compressor to an engine propelling the vehicle under predetermined conditions; activating the electric compressor when the engine is off, evacuating a fuel system and an evaporative emission system of the vehicle to a threshold vacuum via an ejector system via a second check valve by commanding open a second canister purge valve and close a first canister purge valve and a canister vent valve, wherein the canister vent valve is in a vent line coupling a fuel vapor canister to atmosphere, the first canister purge valve is in a third conduit originating from the fuel vapor canister, the second canister purge valve is selectively fluidly coupled to the third conduit via a first conduit and to the vent line via a second conduit, the second check valve is in the third conduit downstream of an intersection of the third conduit and a fourth conduit, wherein one end of the fourth conduit is connected to an air intake of the engine at a location downstream of a throttle in the air intake and another end is connected to the third conduit at a location between the first canister purge valve and the second check valve; in the event that the electric compressor is off and the engine is spinning without fuel to create negative pressure in the air intake of the engine, evacuating the fuel system and the evaporative emission system to a threshold vacuum via a first check valve by commanding open a second canister purge valve and close a first canister purge valve and a canister vent valve, wherein the first check valve is in the fourth conduit, and based on whether the threshold vacuum is reached, indicating whether the first check valve and the second check valve are functioning as needed, or based on a pressure rise in the fuel system and the evaporative emission system after the threshold vacuum is reached, indicating the presence or absence of non-significant undesirable evaporative emissions.

2. The method of claim 1, wherein evacuating the fuel system and the evaporative emission system via activating the electric compressor further comprises fluidly coupling the fuel system and the evaporative emission system to an ejector system of the vehicle, wherein the ejector system functions to evacuate the fuel system and the evaporative emission system when the electric compressor is activated.

3. The method of claim 1, further comprising in response to reaching the threshold vacuum, sealing the fuel system and the evaporative emission system from atmosphere and the engine so as to indicate the presence or absence of non-significant undesirable evaporative emissions based on the pressure rise in the fuel system and the evaporative emission system.

4. The method of claim 1, wherein indicating the presence or absence of non-significant undesirable evaporative emissions based on the pressure rise in the fuel system and the evaporative emission system further comprises: in response to the pressure rise being greater than a predetermined pressure rise threshold, or in response to a rate of the pressure rise being greater than a predetermined pressure rise rate threshold, indicating the presence of non-significant undesirable evaporative emissions for a predetermined duration.

5. The method of claim 1, wherein in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, indicating that there are no significant undesirable evaporative emissions in the fuel system and the evaporative emissions system; and indicating that a second check valve located upstream of the injector system is functioning as desired.

6. The method of claim 5, wherein in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, followed by a condition of negative pressure in an air intake of the engine with the electric compressor being off; indicating whether the threshold vacuum was reached during evacuation of the fuel system and the evaporative emissions system with the condition of negative pressure in the air intake of the engine; and in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system with the condition of negative pressure, indicating that a first check valve located upstream of the air intake is functioning as desired.

7. The method of claim 6, the method further comprising: in response to the threshold vacuum not being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, and further in response to the threshold vacuum not being reached during evacuation of the fuel system and the evaporative emissions system with the condition of negative pressure in the air intake of the engine, indicating that there are significant undesirable evaporative emissions in the fuel system and / or the evaporative emissions system.

8. The method of claim 6, the method further comprising: in response to the threshold vacuum being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, but not being reached during evacuation of the fuel system and the evaporative emissions system with the condition of negative pressure in the air intake of the engine, indicating that the first check valve is stuck closed and indicating that there are no significant undesirable evaporative emissions in the fuel system and the evaporative emissions system; and in response to the threshold vacuum not being reached during evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor, but being reached during evacuation of the fuel system and the evaporative emissions system with the condition of negative pressure in the air intake of the engine, indicating that the second check valve is stuck closed and indicating that there are no significant undesirable evaporative emissions in the fuel system and the evaporative emissions system.

9. The method of claim 6, wherein evacuation of the fuel system and the evaporative emissions system via activation of the electric compressor further comprises drawing air and fuel vapor from a fuel tank located in the fuel system through an entirety of a fuel vapor canister located in the evaporative emissions system before the air and fuel vapor is delivered to the engine, the fuel vapor canister being configured to adsorb fuel vapor from the fuel tank; and ​ Wherein evacuating the fuel system and the evaporative emissions system under conditions of negative pressure in the intake of the engine comprises pumping air and fuel vapor through the monolith of the fuel vapor canister from the fuel tank, wherein the negative pressure in the intake is generated via spinning the engine without fuel.

10. A system for a vehicle, the system comprising: an engine comprising an intake; a motor configured to spin the engine without fuel; a fuel system comprising a fuel tank fluidly coupled to an evaporative emissions system comprising a fuel vapor canister; a canister vent valve in a vent line coupling the fuel vapor canister to atmosphere; a first canister purge valve in a third conduit sourcing from the fuel vapor canister; a second canister purge valve selectively fluidly coupled to the third conduit via a first conduit and to the vent line via a second conduit; a first check valve in a fourth conduit, one end of the fourth conduit connected to the intake at a location downstream of a throttle in the intake of the engine, the other end connected to the third conduit at a location between the first canister purge valve and a second check valve; the second check valve in the third conduit downstream of the intersection of the third conduit and the fourth conduit; an ejector system downstream of the second check valve; an electric compressor in the intake upstream of an intake throttle and configured to supply air to the engine; a fuel tank pressure sensor between the fuel tank and the fuel vapor canister; and a controller storing instructions in a non-transitory memory that, when executed, cause the controller to: in a first condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the first check valve by spinning the engine without fuel via the motor to generate a vacuum in the intake of the engine to evacuate the fuel system and the evaporative emissions system; in a second condition, evacuate the fuel system and the evaporative emissions system by commanding the canister vent valve closed, commanding the first canister purge valve closed, commanding the second canister purge valve open, and evacuating the fuel system and the evaporative emissions system via the second check valve via the ejector system with the electric compressor activated. ​ whether a threshold vacuum is reached during evacuation of the fuel system and the evaporative emission system under both the first condition and the second condition, indicative of the presence or absence of significant undesirable evaporative emissions, and indicative of whether the first check valve and the second check valve are functioning as desired, wherein the threshold vacuum is indicated via the fuel tank pressure sensor; and based on a pressure rise in the fuel system and the evaporative emission system as indicated via the fuel tank pressure sensor after the threshold vacuum is reached and after the fuel system and the evaporative emission system are sealed from the intake of the engine and from atmosphere under either or both of the first condition and / or the second condition, indicative of the presence or absence of non-significant undesirable evaporative emissions in the fuel system and the evaporative emission system.

11. The system of claim 10, wherein the controller stores additional instructions to indicate that both the first check valve and the second check valve are functioning as desired and that there are no significant undesirable evaporative emissions in response to the threshold vacuum being reached under both the first condition and the second condition.

12. The system of claim 10, wherein the controller stores additional instructions to indicate that the first check valve is stuck closed but the second check valve is functioning as desired and that there are no significant undesirable evaporative emissions in response to the threshold vacuum being reached under the second condition but not the first condition; to indicate that the second check valve is stuck closed but the first check valve is functioning as desired and that there are no significant undesirable evaporative emissions in response to the threshold vacuum being reached under the first condition but not the second condition; and and to indicate that there are significant undesirable evaporative emissions in response to the threshold vacuum not being reached during either the first condition or the second condition.

13. The system of claim 10, wherein the controller stores additional instructions to, in response to the threshold vacuum being reached under either or both of the first condition and / or the second condition, seal the fuel system and the evaporative emission system by commanding the second canister purge valve to close and commanding or maintaining the canister vent valve and the first canister purge valve to close; monitor the pressure in the fuel system and the evaporative emission system via the fuel tank pressure sensor; and indicate that there are non-significant undesirable evaporative emissions in response to a pressure rise in the fuel system and the evaporative emission system being greater than a pressure rise threshold or in response to a rate of pressure rise in the fuel system and the evaporative emission system being greater than a rate of pressure rise threshold for a predetermined duration.

14. The system of claim 10, wherein evacuating the fuel system and the evaporative emission system under both the first condition and the second condition includes drawing air and fuel vapor from the fuel system through the entirety of the fuel vapor canister. ​

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