Systems and methods for lapless fuel replacement systems

Abstract

The present disclosure provides a system and method for a coverless refueling system. Methods and systems are provided for a coverless refueling system for a vehicle. In one example, a method may include diagnosing a door seal of an uncapped unit of the uncapped refueling system. The diagnosis includes determining a condition of the door seal in response to the presence of a leak in the evaporative emission system.

Description

Technical Field

[0001] This specification generally relates to methods and systems for diagnosing a fuel fillerless fueling system. Background Art

[0002] Vehicles may utilize a fuel fillerless fueling system to improve the efficiency and convenience of fueling. The fuel fillerless fueling system may include a fuel fillerless unit having a port for receiving a fueling nozzle, the port being configured with two pivotable flaps, hereinafter referred to as baffles, the two pivotable flaps allowing fuel to be added to the vehicle's fuel tank. By eliminating the removal and replacement of the fuel tank cap during a fueling event, evaporative emissions can be reduced while the fueling process can be simplified.

[0003] Over time, debris such as dust, salt, leaves, etc. may accumulate in the fuel fillerless unit, which may interfere with the ability of the baffles to seal the port. Thus, fuel vapors from the fuel tank may escape into the atmosphere through the degraded seals of the baffles. In addition, detecting a leak at the fuel fillerless unit may cause a diagnostic trouble code (DTC) to be set, which may be displayed to the operator at the vehicle instrument panel. Although instructions for resolving the DTC may be included in the vehicle's operation manual, if the operator does not find the instructions, the DTC may evolve into illuminating a malfunction indicator lamp (MIL). Observing the MIL may prompt the operator to repair the vehicle, but only determining this problem does not require repair.

[0004] In addition, the DTC may be incorrect. For example, the DTC may request the operator to perform a fuel fillerless cleaning procedure. However, if the leak in the fuel fillerless unit is not due to the baffles but due to degraded door seals, the DTC may be repeatedly set and cause customer dissatisfaction. Summary of the Invention

[0005] Attempts to address leaks in the fuel fillerless fueling system include using engine vacuum to clean the fuel fillerless fueling system. An exemplary method is shown by Dudar et al. in U.S. 9,724,736. Therein, if a leak is detected after a fueling event but not during the fueling event, engine vacuum may be used to clean the fuel fillerless fueling system. Engine vacuum may be transferred to the fuel fillerless fueling system by closing the fuel vapor canister vent valve and opening the fuel vapor canister purge valve for a period of time. By exposing the fuel fillerless fueling system to engine vacuum, contaminants (e.g., debris) in the fuel fillerless unit of the fuel fillerless fueling system may be forced into the fuel tank, thereby allowing the fuel fillerless unit to seal.

[0006] In addition, cleaning the fuel fillerless unit may not clean the door seals, and the leak may still exist. Moreover, cleaning cannot determine whether the door seals of the fuel fillerless unit are degraded.

[0007] In one example, the above problem can be solved by a method for diagnosing a door seal of a fuel filler unit of a fuel filler system by generating a vacuum in the fuel filler system without a cap. In this way, after diagnosis, the source of leakage can be attributed to the door seal.

[0008] As an example, a flap of the fuel filler unit can be opened in response to the vacuum. If the door seal deteriorates or becomes fouled, the vacuum in the evaporative emission system may not be maintained. This may cause the flap to open and close repeatedly, which may be sensed as multiple pressure inflection points, and the leakage is attributed to the door seal. If the door seal has not deteriorated, only one inflection point may be sensed, indicating the non-deteriorated condition of the door seal. If only one pressure inflection point is sensed, the leakage may not be attributed to the door seal.

[0009] It should be understood that the above summary is provided to introduce in a simplified form a series of concepts that are further described in the detailed description. This does not mean identifying the key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims that follow the detailed description. Moreover, the claimed subject matter is not limited to embodiments that solve any disadvantages recited above or in any other part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 An example of a vehicle system in which a fuel filler system without a cap can be implemented is shown.

[0011] Figure 2 An example of an evaporative emission control (Evap) system of an engine system is shown.

[0012] Figure 3 An example of a fuel filler unit of a fuel filler system without a cap is shown.

[0013] Figure 4 A method for performing diagnosis of a fuel filler unit is shown.

[0014] Figure 5 A graph showing an operation sequence in which a door seal passes a diagnosis is shown.

[0015] Figure 6 A graph showing an operation sequence in which a door seal fails a diagnosis is shown.

[0016] Figure 3 Shown generally to scale. DETAILED DESCRIPTION

[0017] The following description relates to systems and methods for a fuel filler system without a cap. The fuel filler system without a cap can be used in a vehicle system that relies on fuel combustion at an engine for propulsion. Figure 1An example of such a vehicle system is depicted. The engine may include an evaporative emissions control (Evap) system, such as Figure 2 shown. Figure 3 An example of a capless unit is shown in Figure 4 A method for performing diagnostics of a capless unit is shown. Figure 5 A graph showing an operation sequence in which a door seal passes diagnostics is shown. Figure 6 A graph showing an operation sequence in which a door seal fails diagnostics is shown.

[0018] Figures 2 to 3 An exemplary configuration with the relative positioning of various components is shown. In at least one example, such elements may be referred to as being in direct contact or directly coupled, respectively, if shown as being in direct contact or directly coupled to each other. Similarly, in at least one example, elements shown as being adjacent or neighboring to each other may be adjacent or neighboring to each other, respectively. As one example, components in coplanar contact with each other may be referred to as being in coplanar contact. As another example, in at least one example, elements positioned apart from each other with only space therebetween and no other components therebetween may be referred to as such. As yet another example, elements shown as being above / below each other, on opposite sides of each other, or on the left / right sides of each other may be referred to as being so relative to each other. Further, as shown in the drawings, in at least one example, the topmost element or the topmost vertex of an element may be referred to as the "top" of the component, and the bottommost element or the bottommost point of an element may be referred to as the "bottom" of the component. As used herein, top / bottom, upper / lower, above / below may be with respect to the vertical axis of the drawing and are used to describe the positioning of the elements of the drawing relative to each other. Thus, in one example, an element shown as being above other elements is directly above the other elements. As yet another example, the shapes of the elements depicted within the drawing may be referred to as having those shapes (e.g., such as being circular, straight, planar, curved, rounded, chamfered, angled, etc.). Further, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. Still further, in one example, an element shown as being within another element or shown as being outside another element may be referred to as such.

[0019] Now turning to Figure 1, which shows an exemplary vehicle system 100. The vehicle system 100 includes a fuel combustion engine system 110 and a motor 120. As a non-limiting example, the engine system 110 is an internal combustion engine, and the motor 120 is an electric motor. The motor 120 can be configured to utilize or consume an energy source different from that of the engine system 110. For example, the engine system 110 can consume liquid fuel (e.g., gasoline) to produce an engine output, while the motor 120 can consume electrical energy to produce a motor output. Thus, the vehicle system 100 can be referred to as a hybrid electric vehicle (HEV).

[0020] The vehicle system 100 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 system 110 to remain in an off state (e.g., set to a deactivated state), where fuel combustion at the engine stops. For example, under selected operating conditions, when the engine system 110 is deactivated, the motor 120 can propel the vehicle via the drive wheels 130 as indicated by arrow 122.

[0021] During other operating conditions, the engine system 110 can be set to the deactivated state (as described above), and the motor 120 can be operated to charge the energy storage device 150. For example, the motor 120 can receive wheel torque from the drive wheels 130 as indicated by arrow 122, where the motor can convert the vehicle's kinetic energy into electrical energy for storage at the energy storage device 150 as indicated by arrow 124. Thus, in some embodiments, the motor 120 can provide a generator function. However, in other embodiments, a generator 160 can alternatively receive wheel torque from the drive wheels 130, where the generator can convert the vehicle's kinetic energy into electrical energy for storage at the energy storage device 150 as indicated by arrow 162.

[0022] During still other operating conditions, the engine system 110 can operate by burning fuel received from the fuel system 340 as indicated by arrow 142. For example, when the motor 120 is deactivated, the engine system 110 can be operated to propel the vehicle via the drive wheels 130 as indicated by arrow 112. During other operating conditions, both the engine system 110 and the motor 120 can each operate to propel the vehicle via the drive wheels 130 as indicated by arrows 112 and 122, respectively. The configuration where both the engine and the motor can selectively propel the vehicle can be referred to as a parallel-type vehicle propulsion system. It should be noted that in some embodiments, the motor 120 can propel the vehicle via a first set of drive wheels, and the engine system 110 can propel the vehicle via a second set of drive wheels.

[0023] In other embodiments, the vehicle system 100 may be configured as a series vehicle propulsion system, where the engine does not directly propel the drive wheels. Instead, the engine system 110 may be operated to power the motor 120, which may in turn propel the vehicle via the drive wheels 130, as indicated by arrow 122. For example, during selected operating conditions, the engine system 110 may drive the generator 160 as indicated by arrow 116, and the generator may in turn do one or more of the following: supply electrical energy to the motor 120 as indicated by arrow 114 or to the energy storage device 150 as indicated by arrow 162. As another example, the engine system 110 may be operated to drive the motor 120, which may in turn provide a generator function to convert the engine output into electrical energy, where the electrical energy may be stored in the energy storage device 150 for subsequent use by the motor.

[0024] The fuel system 140 may include one or more fuel storage tanks 144 for storing fuel on the vehicle. For example, the fuel tank 144 may store one or more liquid fuels, including but not limited to: gasoline, diesel, and alcohol fuels. In some examples, the fuel may be stored on the vehicle as a blend of two or more different fuels. For example, the fuel tank 144 may be configured to store a blend of gasoline and ethanol (e.g., E10, E85, etc.) or a blend of gasoline and methanol (e.g., M10, M85, etc.), whereby these fuels or fuel blends may be delivered to the engine system 110 as indicated by arrow 142. Other suitable fuels or fuel blends may be supplied to the engine system 110, where they may be burned at the engine to produce an engine output. The engine output may be used to propel the vehicle as indicated by arrow 112 or to recharge the energy storage device 150 via the motor 120 or the generator 160.

[0025] The fuel system 140 may periodically receive fuel from a fuel source residing outside the vehicle. As a non-limiting example, the vehicle system 100 may receive fuel via a fuel dispensing device 170 as indicated by arrow 172 to replenish the fuel. In some embodiments, the fuel tank 144 may be configured to store the fuel received from the fuel dispensing device 170 until it is supplied to the engine system 110 for combustion. In some embodiments, the control system 190 may receive an indication of the level of fuel stored at the fuel tank 144 via a fuel level sensor. The fuel level stored at the fuel tank 144 (e.g., as identified by the fuel level sensor) may be communicated to the vehicle operator, for example, via a fuel gauge or an indication in the vehicle instrument panel 196.

[0026] In one example, as further described below, the fuel system 140 may include a capless fuel refueling system, as Figure 2 shown. The capless fuel refueling system may include a capless unit, asFigure 3 As shown in detail in Figure 3 , the capless unit is configured to receive and dock with the fuel dispensing device 170. The capless unit may include at least two pivotable flaps or baffles disposed in the receiving port of the capless unit, the baffles being configured to seal the receiving port and the fuel tank 144 from the surrounding atmosphere. The fuel dispensing device 170 may be inserted into the receiving port of the capless unit to deliver fuel to the fuel tank 144. For example, as the fuel dispensing device 170 is pushed into the receiving port, the fuel dispensing device 170 may exert a force on the baffles, causing the baffles to pivot towards the inner wall of the receiving port to accommodate the positioning of the fuel dispensing device 170 within the receiving port. In some cases, debris may enter or accumulate at the capless unit, thereby inhibiting the sealing ability of the baffles, and a flag may be set in response. In some examples, a flag may be set when the door seal of the capless unit deteriorates. The diagnosis of the door seal is described in more detail below.

[0027] In some embodiments, the energy storage device 150 may be configured to store electrical energy, which may be supplied to other electrical loads (other than the motor) residing on the vehicle, including cabin heating and air conditioning, engine starting, headlights, cabin audio and video systems, and the like. As a non-limiting example, the energy storage device 150 may include one or more batteries and / or capacitors.

[0028] The control system 190 may communicate with one or more of the engine system 110, the motor 120, the fuel system 140, the energy storage device 150, and the generator 160. For example, the control system 190 may receive sensed feedback information from one or more of the engine system 110, the motor 120, the fuel system 340, the energy storage device 150, and the generator 160. Additionally, the control system 190 may send control signals to one or more of the engine system 110, the motor 120, the fuel system 340, the energy storage device 150, and the generator 160 in response to the sensed feedback. The control system 190 may receive an indication of an operator request for an output of the vehicle propulsion system from the vehicle operator 102. For example, the control system 190 may receive sensed feedback from a pedal position sensor 194 that communicates with a pedal 192. The pedal 192 may schematically refer to a friction pedal and / or a power pedal.

[0029] As indicated by arrow 184, the energy storage device 150 can periodically receive electrical energy from a power source 180 (e.g., not part of the vehicle) residing outside the vehicle. As a non-limiting example, the vehicle system 100 can be configured as a plug-in hybrid electric vehicle (PHEV), where electrical energy can be supplied from the power source 180 to the energy storage device 150 via an electrical energy transmission cable 182. During the operation of recharging the energy storage device 150 from the power source 180, the power transmission cable 182 can electrically couple the energy storage device 150 and the power source 180. When the vehicle propulsion system operates to propel the vehicle, the power transmission cable 182 can be disconnected between the power source 180 and the energy storage device 150. The control system 190 can identify and / or control the amount of electrical energy stored at the energy storage device, and the amount of electrical energy can be referred to as the state of charge (SOC).

[0030] In other embodiments, the power transmission cable 182 can be omitted, where electrical energy can be received wirelessly from the power source 180 at the energy storage device 150. For example, the energy storage device 150 can receive electrical energy from the power source 180 via one or more of electromagnetic induction, radio waves, and electromagnetic resonance. Thus, it should be understood that any suitable method can be used to recharge the energy storage device 150 from a power source not included in the vehicle. In this way, the motor 120 can propel the vehicle by utilizing an energy source different from the fuel utilized by the engine system 110.

[0031] In one example, the vehicle control system 190 can be coupled to a network, such as a cloud-based network. Additionally, the vehicle can be coupled to the remote servers and controllers of one or more other vehicles. Additionally, the vehicle control system 190 can be communicatively coupled to the operator's mobile device via cloud-based communication, so that messages related to engine operation or vehicle system status can be communicated to the driver via the operator's mobile device.

[0032] Figure 2 A schematic diagram of a prior art example of a vehicle system 206 is shown. The vehicle system 206 includes an engine system 208 coupled to an evaporative emissions control system 251 and a fuel system 218. The evaporative emissions control system 251 (also referred to as the evaporative emissions system 251) includes a first charcoal canister 222 and a second charcoal canister 201 that can be used to capture and store fuel vapors. Although only two charcoal canisters are shown, the evaporative emissions control system 251 can include three or more charcoal canisters. In some examples, the vehicle system 206 can be a hybrid electric vehicle system, such as Figure 1 the vehicle propulsion system 100. Thus, the engine 210 can be the same as Figure 1 the engine 110, while Figure 2 the control system 214 can be the same as Figure 1 the control system 190.

[0033] The engine system 208 may include an engine 210 having a plurality of cylinders 230. The engine 210 includes an engine intake port 223 and an engine exhaust port 225. The engine intake port 223 includes a throttle 263 fluidly coupled to an intake manifold 244. Fresh intake air enters an intake passage 242 and flows through an air cleaner 253. The air cleaner 253 located in the intake passage 242 may clean the intake air before the intake air is directed to the intake manifold 244. The cleaned intake air exiting the air cleaner 253 may flow through the throttle 263 (also referred to as the intake throttle 263) via the intake passage 242 into the intake manifold 244. Thus, when fully open, the intake throttle 263 enables a higher level of fluid communication between the intake manifold 244 and the intake passage 242 downstream of the air cleaner 253. The amount of intake air supplied to the intake manifold 244 may be controlled via the throttle 263 based on engine conditions. The engine exhaust port 225 includes an exhaust manifold 248 leading to an exhaust passage 235 that directs exhaust to the atmosphere. The engine exhaust port 225 may include one or more emission control devices 270 that may be installed at a close-coupled location in the exhaust port. The one or more emission control devices may include a three-way catalytic converter, a lean NO x trap, a diesel particulate filter, an oxidation catalyst, etc. It should be understood that other components, such as various valves and sensors, may be included in the engine.

[0034] Each cylinder 230 may be served by one or more valves. In this example, each cylinder 230 includes a corresponding intake valve 264 and an exhaust valve (not shown). Each intake valve 264 may be held in a desired position via a corresponding spring. The engine system 208 also includes one or more camshafts 268 for operating the intake valves 263. In the depicted example, the intake camshaft 268 is coupled to the intake valves 264 and may be actuated to operate the intake valves 264. In some embodiments, where the intake valves of a plurality of cylinders 230 are coupled to a common camshaft, the intake camshaft 268 may be actuated to operate all of the intake valves of all of the coupled cylinders.

[0035] The intake valve 264 may be actuated between an open position that allows intake air to enter the corresponding cylinder and a closed position that substantially blocks intake air from the cylinder. The intake camshaft 268 may be included in an intake valve actuation system 269. The intake camshaft 268 includes an intake cam 267 having a cam lobe profile for opening the intake valve 264 during a defined intake duration. The lobe profile may affect cam lift height, cam duration, and / or cam timing. A controller, such as controller 212, may be capable of switching the intake valve duration by longitudinally moving the intake cam lobe 268 and switching between cam profiles.

[0036] It should be understood that the intake camshaft and / or the exhaust camshaft can be coupled to a sub-group of cylinders, and there can be multiple intake camshafts and / or exhaust camshafts. The intake valve actuation system 269 can also include push rods, rocker arms, tappets, etc. Thus, the intake valve actuation system can include multiple electromechanical actuators. Such devices and features can control the actuation of the intake valve 264 by converting the rotational motion of the cam into the translational motion of the valve. As previously discussed, the valve can also be actuated via additional cam lobe profiles on the camshaft, where the cam lobe profiles between different valves can provide varying cam lift heights, cam durations, and / or cam timings. However, alternative camshaft (overhead and / or pushrod) arrangements can be used if desired. Additionally, in some examples, the cylinders 230 can each have more than one exhaust valve. In other examples, the intake valves 264 of one or more cylinders can be actuated by a common camshaft. Further still, in some examples, some of the intake valves 264 can be actuated by their own independent camshafts or other devices.

[0037] The engine system 208 can include a variable valve timing system, e.g., a variable cam timing (VCT) system 260. Thus, the VCT system 260 can be operably and communicatively coupled to the intake valve actuation system 269. The VCT system 260 can include an intake camshaft phaser 265 that is coupled to a common intake camshaft 268 to change the intake valve timing. The VCT system 260 can be configured to advance or retard the valve timing by advancing or retarding the cam timing and can be controlled by the controller 212. In some embodiments, the valve timing can be changed by a continuously variable valve lift (CVVL) device, such as intake valve closing (IVC).

[0038] The above-described valve / cam control devices and systems can be hydraulically driven, or electrically actuated, or a combination thereof. In one example, the position of the camshaft can be changed via cam phase adjustment of an electric actuator (e.g., an electrically actuated cam phaser) that has a fidelity exceeding that of most hydraulically operated cam phasers. A signal line can send control signals to the VCT system 260 and can receive cam timing and / or cam selection measurements from the VCT system. Thus, the above-described intake valve actuation system can effect closing of the intake valve to block fluid flow therethrough when needed.

[0039] Although Figure 2is not shown, but the vehicle system 206 may also include an exhaust gas recirculation (EGR) system to direct a desired portion of the exhaust from the exhaust passage 235 to the intake manifold 244 via an EGR passage. The controller 212 may vary the amount of EGR provided by adjusting an EGR valve in the EGR passage. By introducing exhaust gas into the engine 210, the amount of available oxygen for combustion is reduced, thereby reducing the combustion flame temperature and reducing, for example, NO x formation.

[0040] The fuel system 218 may include a fuel tank 220 coupled to a fuel pump system 221. The fuel pump system 221 may include one or more pumps for pressurizing fuel delivered to an injector (such as the exemplary injector 266) of the engine 210. Although only a single injector 266 is shown, additional injectors are provided for each cylinder. It should be understood that the fuel system 218 may be a returnless fuel system, a return fuel system, or various other types of fuel systems. The fuel tank 220 may store a variety of fuel blends, including fuels having a range of alcohol content, such as various gasoline-ethanol blends (including E10, E85, gasoline, etc.) and combinations thereof. A fuel level sensor 234 located in the fuel tank 220 may provide an indication of the fuel level (“fuel level input”) to the controller 212. As depicted, the fuel level sensor 234 may include a float connected to a variable resistor. Alternatively, other types of fuel level sensors may be used.

[0041] Vapors generated in the fuel system 218 may be directed via a vapor recovery line 231 to an evaporative emissions control system 251, which includes a first fuel vapor canister 222 and a second fuel canister 201. The first fuel vapor canister 222 may also be simply referred to as the first canister 222, and the second fuel vapor canister 201 may be referred to herein as the second canister 201. The fuel vapors stored in the first canister 222 and the second canister 201 may later be drawn into the engine intake port 223. The vapor recovery line 231 may be coupled to the fuel tank 220 via one or more conduits and may include one or more valves for isolating the fuel tank during certain conditions. For example, the vapor recovery line 231 may be coupled to the fuel tank 220 via one or more of the conduits 271, 273, and 275 or a combination thereof.

[0042] In addition, in some examples, one or more fuel tank vent valves are located in conduits 271, 273, or 275. Among other functions, the fuel tank vent valves can also allow the fuel vapor canister of the emissions control system to remain at a low pressure or in a vacuum without increasing the fuel evaporation rate of the fuel tank (which would otherwise occur when the fuel tank pressure decreases). For example, conduit 271 can include a grade vent valve (GVV) 287, conduit 273 can include a fill limit vent valve (FLVV) 285, and conduit 275 can include a grade vent valve (GVV) 283. In addition, in some examples, the recovery line 231 can be coupled to the fuel filling system 219 (or the fuel refueling system 219). In some examples, the fuel filling system can include a capless unit 258 for sealing off the fuel filling system from the atmosphere. The fuel refueling system 219 is coupled to the fuel tank 220 via a fuel fill tube or neck 211.

[0043] The capless unit 258 can be configured to receive a fuel dispensing device, such as Figure 1 the fuel dispensing device 170, without the need to remove a cap. In addition, the capless unit 258 enables the fuel system 140 to be sealed off from air outside the fuel system 140 (e.g., the air outside and surrounding the fuel system 140). For example, the capless unit 258 can include two pivotable flaps (e.g., flap valves or baffles) 262 disposed in the receiving port of the capless unit 258, and the two pivotable flaps yield to the pressure applied by the fuel dispensing device and pivot to allow the nozzle of the fuel dispensing device to be inserted into the receiving port. The baffles 262 can be spring-loaded such that when the fuel dispensing device is removed, the baffles 262 close and seal the capless unit 258.

[0044] The evaporative emissions control system 251 can include one or more emissions control devices, such as one or more fuel vapor canisters filled with a suitable adsorbent. The canisters are configured to temporarily trap fuel vapors (including evaporated hydrocarbons) during fuel tank filling operations and "running losses" (i.e., fuel evaporated during vehicle operation). In one example, the adsorbent used is activated carbon. The evaporative emissions system 251 can also include a canister exhaust path or exhaust line 227 that can vent gases from the canister 222 to the atmosphere when storing or trapping fuel vapors from the fuel system 218.

[0045] When stored fuel vapor is drawn from the first canister 222 and the second canister 201 to the engine intake 223 via the draw line 228 and the canister draw valve 261 (also referred to as the draw valve 261), the exhaust line 227 can allow fresh air to be drawn into the canister 222. For example, the draw valve 261 can be normally closed but can be opened during certain conditions such that vacuum from the engine intake manifold 244 is provided to the fuel vapor canister 222 for drawing.

[0046] The FTIV 252 can be located within the conduit 278 between the fuel tank 220, the first canister 222, and the second canister 201. The FTIV 252 can be a normally closed valve that, when opened, allows fuel vapor to be discharged from the fuel tank 220 via the conduit 278 to only the first canister 222, via the conduit 279 to only the second canister 201, or both. The fuel vapor can be stored within the first canister 222 and the second canister 201, and the air with the fuel vapor removed can then be discharged to the atmosphere via the exhaust line 227. At a later time when draw conditions exist, the fuel vapor stored within the first canister 222 and the second canister 201 can be drawn via the canister draw valve 261 along the draw line 228 to the engine intake 223. Thus, the FTIV 252 can isolate and seal the fuel tank 220 from the evaporative emission system 251 when closed. It should be noted that some vehicle systems may not include the FTIV 252.

[0047] The fuel system 218 can be operated in multiple modes by the controller 212 by selectively adjusting various valves and solenoids. For example, the fuel system can be operated in a fuel vapor storage mode (e.g., during fuel tank refueling operations and with the engine not running), where the controller 212 can open the FTIV 252 while closing the canister draw valve (CPV) 261 to introduce refueling vapor directly into the first and second canisters while preventing the fuel vapor from being directed to the intake manifold.

[0048] As another example, the fuel system can be operated in a refueling mode (e.g., when the vehicle operator requests fuel tank refueling), where the controller 212 can open the FTIV 252 while keeping the CPV 261 closed to depressurize the fuel tank before allowing fuel to be added to the fuel tank. Thus, the FTIV 252 can remain open during refueling operations to allow refueling vapor to be stored in the canister. After refueling is complete, the FTIV can be closed.

[0049] As yet another example, the fuel system may operate in a canister purge mode (e.g., when the emission control device light-off temperature has been reached and the engine is running), where the controller 212 may open the CPV 261 while closing the FTIV 252. Here, the vacuum generated by the intake manifold of the operating engine may be used to draw fresh air through the exhaust pipe line 227 and through the first canister 222 and the second canister 201 to purge stored fuel vapor into the intake manifold 244. In this mode, the fuel vapor purged from the canister is burned in the engine. The purge may continue until the amount of fuel vapor stored in the canister is below a threshold. The FTIV 252 may be closed during the purge mode.

[0050] The evaporative leak check module (ELCM) 295 may be coupled to the vent line 227 on a side of the canister 201 opposite the CPV 261. In this way, the ELCM 295 may be positioned between the canister 201 and the atmosphere. In particular when the vacuum at the intake manifold 244 is not available or is equal to a determined value, the ELCM 295 may be used to diagnose leaks in the Evap system. For example, the ELCM 295 may include a vacuum pump 296, allowing the ELCM 295 to provide a reference check of the pressure in the fuel system 218 when the vacuum pump 296 is activated to draw pressure on a reference orifice of the ELCM 295. The resulting pressure measured by the ELCM pressure sensor 297 at the reference orifice may be used as a reference for detecting leaks.

[0051] The canister vent valve (CVV) 293 may optionally be positioned downstream of the ELCM 295 between the ELCM 295 and the atmosphere. The CVV 293 may be configured to isolate the evaporative emission system from the atmosphere when in the closed position. The CVV 293 may vent gases from the evaporative emission system to the atmosphere when in the open position. In one example, the CVV 293 may be integrated into the ELCM 295 as a switching valve.

[0052] The controller 212 may include a part of the control system 214. The control system 214 is shown as receiving information from a plurality of sensors 216 (various examples of which are described herein) and sending control signals to a plurality of actuators 281 (various examples of which are described herein). As an example, the sensors 216 may include a manifold absolute pressure (MAP) sensor 224, an atmospheric pressure (BP) sensor 246, an exhaust sensor 226 located in the exhaust manifold 248 upstream of the emission control device, a temperature sensor 233, a fuel tank pressure sensor 291 (also known as a fuel tank pressure transducer or FTPT), and canister temperature sensors 232, 203. Other sensors (such as pressure, temperature, air-fuel ratio, and composition sensors) may be coupled to various locations in the vehicle system 206. As another example, the actuators may include a CPV 261, a fuel injector 266, a throttle 263, an FTIV 252, a fuel pump 221, and a fuel fill lock 245. The control system 214 may include the controller 212. The controller may receive input data from various sensors, process the input data, and trigger the actuators in response to the processed input data based on instructions or codes corresponding to one or more routines programmed therein.

[0053] The controller 212 receives signals from Figure 2 various sensors and employs Figure 2 various actuators to adjust engine operation based on the received signals and instructions stored in the controller's memory. For example, adjusting the canister purge valve may include adjusting the actuator of the canister purge valve to adjust the flow rate of fuel vapor passing therethrough. Thus, the controller 212 may transmit a signal to the actuator of the canister purge valve (e.g., the canister purge valve solenoid) based on a desired purge flow rate. Therefore, the canister purge valve solenoid may be opened (and pulsed) at a specific duty cycle to allow stored vapor to flow from the canister through the purge line 228 to the intake manifold 244.

[0054] Figure 2 The capless unit 258 of Figure 3 is shown in more detail in Figure 1 . Therein, the capless unit 258 has a generally cylindrical geometry with a central axis 301. The capless unit 258 has a shroud 300 surrounding the internal volume of the capless unit 258, and the internal volume forms a receiving port or container 303 of the capless unit 258. As described above, the receiving container 303 is configured to receive the nozzle of a fuel dispensing device (such as Figure 1 the fuel dispensing device 170). The shroud 300 is configured to enclose the components in the assembly. The capless unit 258 further includes an outer housing 302 configured to at least partially enclose the various internal components of the capless unit 258.

[0055] The capless unit 258 further includes Figure 2The first upstream baffle 262a in the baffle 262, the upstream baffle 262a includes a hinge 306. The upstream baffle 262a is embedded from the cover 300. The pre-loaded upstream spring 308 can be coupled to the upstream baffle 262a and the outer housing 302. The pre-loaded upstream spring 308 coupled to the upstream baffle 262a can provide a return force to the door when the door is opened. The upstream spring 308 is configured to provide a return force when the upstream baffle 262a is pressed via the nozzle of the fuel dispensing device. In this way, the upstream baffle 262a can close after the nozzle is removed during a fueling event. Thus, the upstream baffle 262a automatically closes without the assistance of a fueling operator. As a result, the fueling process is simplified.

[0056] The seal 310 can be attached to the upstream baffle 262a. Specifically, in some examples, the seal 310 can extend around the perimeter of the upstream baffle 262a. When the upstream baffle 262a is in the closed position, the seal 310 can be in coplanar contact with the cover 300. In this way, evaporative emissions from the capless unit 258 are reduced. Herein, the seal 310 can be interchangeably referred to as the door seal 310 herein.

[0057] The capless unit 258 further includes a locking lip 312. The locking lip 312 can be configured to receive a portion of the nozzle. In some examples, the locking lip 312 can be provided to extend around at least 100° of the inner circumference of the capless unit 258. The locking lip 312 may affect the positioning and angle of the nozzle axis nozzle during fueling and may therefore affect the filling performance.

[0058] The capless unit 258 further includes an inner housing 314. The wall of the inner housing 314 can define a nozzle housing configured to receive the nozzle. The inner housing 314 can include a nozzle stop actuator 316 configured to actuate a portion of the nozzle that initiates fuel flow from the nozzle.

[0059] An upstream body seal 318 and a downstream body seal 320 can be provided in the capless unit 258 to seal the outer housing 302 and various internal components in the capless unit 258. Specifically, the upstream body seal and the downstream body seal (318 and 320) are configured to extend between the outer housing 302 and the inner housing 314. In some examples, the upstream body seal 318 and / or the downstream body seal 320 can be O-rings.

[0060] The capless unit 258 further includes Figure 2The second downstream baffle 262b in the baffle 262 is positioned downstream of the upstream baffle 262a and the nozzle stop actuator 316. The downstream baffle 262b includes a hinge 323 and has a preloaded downstream spring 324 coupled thereto. The preloaded downstream spring 324 is coupled to the downstream baffle 262b such that when the downstream baffle 262b is opened, a return force is provided to the downstream baffle. The downstream spring 324 is also coupled to the outer housing 302. The downstream spring 324 is configured to provide a return force to the downstream baffle 262b when the downstream baffle 262b is in the open position. The downstream baffle 262b may also include a seal 326 (e.g., a flap seal). In some examples, the seal 326 may be positioned around the perimeter of the downstream baffle 262b. The downstream baffle 262b enables the reduction of evaporative emissions during the fueling process by sealing off the Evap system (e.g., Figure 2 the Evap system 251) from the surrounding atmosphere. Thus, the upstream baffle 262a strengthens the seal of the Evap system and may be configured as a reinforcement of the downstream baffle 262b. In the depicted example, the downstream baffle 262b is arranged perpendicular to the fuel flow when closed. However, other orientations of the downstream baffle 262b are possible.

[0061] The capless unit 258 may be positioned in the Figure 1 vehicle system 100 shown in a variety of configurations. In one example, the capless unit 258 has a downward gradient. In other words, the upstream baffle 262a is positioned vertically above the deflector 350 with respect to the gravity axis 352. In this way, gravity-assisted fuel flow occurs during the fueling operation.

[0062] The capless unit 258 includes a deflector 350 arranged downstream of the downstream baffle 262b. The capless unit 258 also includes Figure 2 the fill tube 260. The deflector 350 may be at least partially enclosed by the fill tube 260 that is in fluid communication with the fuel tank (e.g., the fuel tank 144 as Figure 2 shown).

[0063] The capless unit 258 may also include a vacuum release mechanism (not shown). The vacuum release mechanism may allow a passage in the capless unit 258 to open at a threshold vacuum, thereby allowing the fuel tank to ventilate to the atmosphere. In this way, an excessive fuel tank vacuum will cause the vacuum release mechanism to ventilate to the atmosphere, thus avoiding the vacuum exceeding a determined upper limit value. The vacuum threshold for activating the vacuum release mechanism may be set to, for example, -18 inH 2 O, or set to a suitable threshold, depending on the fuel tank design and configuration. The vacuum threshold may also be set lower than that used for the ELCM (e.g., Figure 2a greater level of vacuum conditions for fuel tank leak testing of the ELCM 295) (e.g., a stronger vacuum). In this way, the ELCM test cycle may not trigger the vacuum release mechanism (triggering the vacuum release mechanism may result in a false fail result), but allows the naturally occurring fuel tank vacuum above the threshold to be released.

[0064] In some embodiments, the vacuum release mechanism may not be an additional hardware component within the capless unit 258. Rather, the preloaded upstream spring 308 and the preloaded downstream spring 324 may be set with a certain tension such that a fuel tank vacuum above the threshold (e.g., -18 inH 2 O) will cause the upstream baffle 262a and the downstream baffle 262b to open, thereby venting the fuel tank to the atmosphere. In some embodiments, the preloaded upstream spring 308 and the preloaded downstream spring 324 may be solenoid-activated springs controlled by a controller (e.g., Figure 2 the controller 212). When the fuel tank vacuum increases to above the threshold vacuum (e.g., determined by Figure 2 the FTPT 291), the controller may deactivate the solenoid, thereby allowing the upstream baffle 262a and the downstream baffle 262b to open, thereby venting the fuel tank to the atmosphere. When the fuel tank vacuum reaches the threshold level, the solenoid may be reactivated.

[0065] Now turning to Figure 4 , which shows a method 400 for performing a diagnosis of the door seal of the capless unit in response to detecting a leak. The instructions for performing method 400 may be executed by a controller based on instructions stored in the controller's memory (e.g., non-transitory memory) in combination with signals received from sensors of the engine system (such as the sensors described above with reference to Figure 1 and Figure 2 ). According to the method described below, the controller may employ the engine actuators of the engine system to adjust engine operation.

[0066] Method 400 begins at 402, which includes determining operating parameters. The operating parameters may include one or more of manifold vacuum, Evap system pressure, fuel tank pressure, and air-fuel ratio. The Evap system pressure may be determined based on feedback from one or more of the FTPT or ELCM pressure. The fuel tank pressure may be determined based on feedback from the FTPT.

[0067] At 404, method 400 may include determining whether a leak is detected. A leak may be detected if the pressure of the Evap system is not equal to a determined threshold. For example, if the Evap system is expected to be equal to a threshold vacuum and the Evap system pressure is greater than the threshold vacuum, there may be a leak. As another example, if an increase in pressure is expected in the fuel tank or the Evap system and the pressure does not increase to the threshold pressure, there may be a leak. In one example, after a fuel fill event, a leak may be detected if the fuel tank pressure does not increase to the threshold pressure. As another example, ambient temperature changes may be used during an engine off condition to determine if there is a leak.

[0068] If no leak is detected (e.g., 404 is NO), then at 406, method 400 may include not performing a door seal diagnostic. There is no leak and no diagnosis of the door seal is requested. The door seal is not deteriorated or fouled.

[0069] If a leak is detected (e.g., 404 is YES), it may be desirable to determine if the door seal is the source of the leak and a diagnosis may be initiated. By diagnosing the door seal, a prompt (e.g., DTC) to request the vehicle operator to clean the capless unit may be corrected.

[0070] The diagnosis may begin at 408, which includes actuating the CVV to the closed position. Thus, the Evap system may be sealed off from the atmosphere.

[0071] At 410, method 400 includes opening the CPV. The intake manifold may be fluidly coupled to the Evap system. In one example, vacuum from the intake manifold may flow to the Evap system.

[0072] In some examples, such as embodiments where the ELCM is included in the Evap system, the CPV may remain closed and the vacuum may be generated by the ELCM. The vacuum may extend through the Evap system and reduce the pressure of the capless unit. Thus, the diagnosis may be used for hybrid and non - hybrid vehicles.

[0073] At 412, method 400 may include monitoring the Evap system pressure. In one example, the Evap system pressure may be monitored via FTPT. After being fluidly connected to the intake manifold, the Evap system pressure may decrease. In one example, the Evap system pressure may decrease from an upper limit pressure to a lower limit pressure. The upper limit pressure and the lower limit pressure may be non - zero values. In one example, the upper limit pressure is equal to atmospheric pressure and the lower limit pressure is equal to a determined negative pressure.

[0074] At 414, method 400 may include determining whether more than one pressure inflection point is sensed. Pressure inflection points may occur due to volume changes in the Evap system caused by the opening of the baffle in the capless unit. Multiple pressure inflection points may occur when vacuum leaks through the door seal and then re - establishes, due to the baffle opening repeatedly.

[0075] If only one pressure inflection point is sensed (e.g., no more than one pressure point is sensed) (e.g., 414 is no), then at 416, method 400 may include determining that the door seal is not deteriorated.

[0076] At 418, method 400 may include not requesting door seal cleaning or replacement. In one example, when diagnosing the door seal, the leak may not be attributed to the door seal, and the system may perform other diagnostic routines to determine the source of the leak.

[0077] If more than one pressure inflection point is sensed (e.g., 414 is yes), then at 420, method 400 may include determining that the door seal of the capless unit is deteriorated.

[0078] At 422, method 400 may include setting a flag (e.g., DTC). The flag may be stored in memory and accessible via a diagnostic inspection device used by a technician. The flag may indicate to the technician via a diagnostic code received by the diagnostic inspection device that door seal repair is requested. In one example, the repair may include replacing the door seal.

[0079] At 424, method 400 may include requesting door seal cleaning or replacement. The request may be sent to the vehicle operator via text, email, phone call, or an alert via the vehicle communication system. For example, a message may be displayed on the screen of the vehicle's infotainment system. Once the door seal is cleaned or replaced and no leak is detected anymore, the flag may be removed.

[0080] In one example, the method may further include automatically cleaning the capless unit in response to door seal leakage. In one example, additional vacuum from the ELCM and / or intake manifold may be directed to the capless unit. Additionally or alternatively, high - pressure air may be directed from the turbocharger and / or a separate supercharger to the capless unit. By flowing vacuum and / or high - pressure air to the capless unit, the door seal can be automatically cleaned without input from the vehicle operator.

[0081] Now turning to Figure 5 which shows the Figures 1 to 3 executed by the system using Figure 4Graph 500 of diagnostics. Graph 510 shows whether a leak in the Evap system is detected. Graph 520 shows feedback from the FTPT. Dashed line 522 shows a threshold pressure, and dashed line 524 shows a threshold vacuum. Graph 530 shows the position of the CPV. Graph 540 shows the position of the CVV. Graph 550 shows whether the door seal is degraded. Time increases from the left side to the right side of the figure.

[0082] Prior to t1, a leak is detected. Leaks may be detected during engine off conditions (such as before and after a refueling event) and / or based on a daytime vapor pressure rise or fall. Additionally or alternatively, the ELCM may be used to determine if a leak exists in the Evap system. The ELCM may apply pressure to the Evap system, and if a determined pressure is not reached, a leak may exist.

[0083] At t1, the CVV is commanded to close. Between t1 and t2, the Evap system is sealed from the atmosphere.

[0084] At t2, the CPV is commanded to open. Between t2 and t3, the Evap system is fluidly coupled to the intake manifold. The pressure of the Evap system can decrease from a threshold pressure toward a threshold vacuum. In one example, the threshold pressure is based on atmospheric pressure, and the threshold vacuum is based on a negative pressure, such as less than -10 inH. 2 O or less than -20inH 2 O.

[0085] At t3, the pressure of the Evap system is equal to the threshold vacuum. Between t3 and t4, an inflection point occurs. The inflection point may include a pressure increase due to the volume increase when the flap of the uncovered unit opens. The vacuum may be reestablished.

[0086] At t4, the pressure of the Evap system is equal to the threshold vacuum. After t4, the pressure of the Evap system is less than the threshold vacuum. Therefore, only one inflection point is sensed, indicating that the vacuum is maintained and the damper remains in the open position. The door seal is determined to be non-degraded.

[0087] Now turn to Figure 6 , which shows the use of Figures 1 to 3 System execution Figure 4 Graph 600 of diagnostics. Graph 610 shows whether a leak in the Evap system is detected. Graph 620 shows feedback from the FTPT. Dashed line 622 shows a threshold pressure, and dashed line 624 shows a threshold vacuum. Graph 630 shows the position of the CPV. Graph 640 shows the position of the CVV. Graph 650 shows whether the door seal is degraded. Time increases from the left side to the right side of the figure.

[0088] Before t1, a leak is detected. The leak can be detected during engine-off conditions (such as before and after a fueling event) and / or based on a rise or fall in the daytime vapor pressure. Additionally or alternatively, an ELCM can be used to determine if there is a leak in the Evap system. The ELCM can apply pressure to the Evap system, and if the determined pressure is not reached, there may be a leak.

[0089] At t1, the CVV is commanded to close. Between t1 and t2, the Evap system is sealed off from the atmosphere.

[0090] At t2, the CPV is commanded to open. Between t2 and t3, the Evap system is fluidly coupled to the intake manifold. The pressure in the Evap system can decrease from a threshold pressure towards a threshold vacuum. In one example, the threshold pressure is based on the atmosphere, and the threshold vacuum is based on a negative pressure, such as less than -10 inH 2 O or less than -20 inH 2 O.

[0091] At t3, the pressure in the Evap system is equal to the threshold vacuum. Between t3 and t4, multiple inflection points occur. Each inflection point can include an increase in pressure due to an increase in volume when the baffle of the capless unit opens. Multiple inflection points may occur due to a leak of vacuum through the door seal of the capless unit. By doing so, the baffle can swing between an open position and a closed position.

[0092] At t4, it is determined that the door seal is deteriorated in response to the multiple inflection points. In one example, in response to sensing a determined number of inflection points, it can be determined that the door seal is deteriorated. For example, it is determined that the door seal is deteriorated in response to sensing more than one inflection point or more than two inflection points.

[0093] The technical effect of diagnosing the door seal of the capless unit can include improving customer satisfaction by reducing the frequency of customer maintenance requests. The diagnosis can determine if the door seal is a source of leakage. If the door seal is the culprit, the vehicle operator can be requested to clean or replace the door seal. By doing so, the vehicle operator can be requested to perform the capless cleaning procedure less frequently.

[0094] The present disclosure provides support for a method that includes diagnosing a door seal of a fuel door unit of a fuel doorless refueling system by creating a vacuum in the fuel doorless refueling system. A first example of the method further includes: wherein creating the vacuum in the fuel doorless refueling system includes fluidly coupling the fuel doorless refueling system to an intake manifold of an engine. A second example of the method (optionally including the first example) further includes: wherein the diagnosing includes determining that the door seal passes in response to sensing only one inflection point during the diagnosing, wherein the only one inflection point is based on the pressure of the fuel doorless refueling system sensed by a fuel tank pressure transducer (FTPT). A third example of the method (optionally including one or more of the foregoing examples) further includes: wherein the diagnosing includes determining that the door seal fails in response to sensing multiple inflection points during the diagnosing. A fourth example of the method (optionally including one or more of the foregoing examples) further includes: wherein creating the vacuum in the fuel doorless refueling system includes opening a baffle in the fuel door unit. A fifth example of the method (optionally including one or more of the foregoing examples) further includes: wherein the diagnosing is initiated in response to a leak being present in an evaporative emissions system. A sixth example of the method (optionally including one or more of the foregoing examples) further includes responding to the diagnosing indicating that the leak is not due to a deteriorated door seal.

[0095] The present disclosure provides additional support for a fueling system for a vehicle without a fuel cap, the fueling system without a fuel cap including: a fuel capless unit having a baffle and configured to receive a nozzle of a fuel dispensing device; and a controller including computer-readable instructions that, when executed, enable the controller to detect the presence of a leak in an evaporative emission system of the vehicle and perform a diagnosis of a door seal of the fuel capless unit by creating a vacuum in the fuel capless unit. A first example of the fueling system without a fuel cap further includes: wherein the evaporative emission system includes a fuel tank pressure sensor (FTPT) configured to sense the pressure of the evaporative emission system. A second example of the fueling system without a fuel cap (optionally including the first example) further includes: wherein the door seal passes the diagnosis in response to sensing only one pressure inflection point during the diagnosis. A third example of the fueling system without a fuel cap (optionally including one or more of the foregoing examples) further includes: wherein the instructions enable the controller to indicate that the leak is not caused by the door seal. A fourth example of the fueling system without a fuel cap (optionally including one or more of the foregoing examples) further includes: wherein the door seal fails the diagnosis in response to sensing multiple pressure inflection points during the diagnosis. A fifth example of the fueling system without a fuel cap (optionally including one or more of the foregoing examples) further includes: wherein the instructions enable the controller to indicate that the leak is caused by the door seal and request cleaning or replacement of the door seal. A sixth example of the fueling system without a fuel cap (optionally including one or more of the foregoing examples) further includes: wherein the evaporative emission system is sealed off from the atmosphere and fluidly coupled to an intake manifold of an engine of the vehicle during the diagnosis. A seventh example of the fueling system without a fuel cap (optionally including one or more of the foregoing examples) further includes: wherein the baffle is actuated in response to the presence of a vacuum.

[0096] The present disclosure provides further support for a method that includes: isolating the evaporative emission system from the atmosphere in response to a detected leak in the evaporative emission system of an engine; creating a vacuum in the evaporative emission system and in a capless fuel filling system that includes a capless unit; monitoring the pressure of the evaporative emission system; and determining the condition of a door seal of the capless unit based on the number of detected pressure inflection points. A first example of the method further includes: wherein determining the condition of the door seal includes determining that the door seal is deteriorated in response to the number of detected pressure inflection points being greater than one. A second example of the method (optionally including the first example) further includes: wherein determining the condition of the door seal includes determining that the door seal is not deteriorated in response to the number of detected pressure inflection points being equal to one. A third example of the method (optionally including one or more of the foregoing examples) further includes: wherein the engine is on during the diagnosis. A fourth example of the method (optionally including one or more of the foregoing examples) further includes requesting maintenance of the door seal in response to determining that the condition of the door seal is deteriorated.

[0097] It should be noted that the example control and estimation routines included herein can be used with a variety of 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 a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific routines described herein can represent any number of processing strategies (such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc.) among one or more. Accordingly, the various actions, operations, and / or functions shown can be executed in the sequence shown, executed in parallel, or in some cases omitted. Similarly, the order of processing is not necessarily required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. One or more of the actions, operations, and / or functions shown can be repeatedly executed according to the particular strategy used. Additionally, the actions, operations, and / or functions can be graphically represented as code to be programmed into the non-transitory memory of a computer-readable storage medium for an engine control system, wherein the actions are implemented by executing the instructions in a system including various engine hardware components in conjunction with an electronic controller.

[0098] It should be understood that the configurations and routines disclosed herein are exemplary in nature and these specific embodiments should not be regarded as having a limiting meaning since many variations are possible. For example, the above techniques 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.

[0099] The appended claims particularly point out certain combinations and sub - combinations that are regarded as novel and non - obvious. These claims may refer to "an" element or "a first" element or their equivalents. Such claims are to be understood as covering the combination of one or more such elements, neither requiring nor precluding two or more such elements. Other combinations and sub - combinations of the disclosed features, functions, elements, and / or properties may be claimed by amending these claims or by presenting new claims in this application or a related application. Such claims, whether broader, narrower, equivalent, or different in scope compared to the original claims, are also regarded as included within the subject matter of this disclosure.

[0100] According to the present invention, a method includes: diagnosing a door seal of a fuel filler unit of a fuel filler system without a cap by creating a vacuum in the fuel filler system without a cap.

[0101] In one aspect of the present invention, creating the vacuum in the fuel filler system without a cap includes fluidly coupling the fuel filler system without a cap to an intake manifold of an engine.

[0102] In one aspect of the present invention, the diagnosing includes determining that the door seal passes in response to sensing only one inflection point during the diagnosis, wherein the only one inflection point is based on the pressure of the fuel filler system without a cap sensed by a fuel tank pressure transducer (FTPT).

[0103] In one aspect of the present invention, the diagnosing includes determining that the door seal fails in response to sensing multiple inflection points during the diagnosis.

[0104] In one aspect of the present invention, creating a vacuum in the fuel filler system without a cap includes opening a baffle in the fuel filler unit.

[0105] In one aspect of the present invention, the diagnosing is initiated in response to the presence of a leak in an evaporative emissions system.

[0106] In one aspect of the present invention, the method includes indicating that the leak is not due to a deteriorated door seal in response to passing the diagnosis.

[0107] According to the present invention, there is provided a fuel filler system without a cap for a vehicle, having: a fuel filler unit having a baffle and configured to receive a nozzle of a fuel dispensing device; and a controller including computer - readable instructions that, when executed, enable the controller to: detect the presence of a leak in an evaporative emissions system of the vehicle; and perform a diagnosis of a door seal of the fuel filler unit by creating a vacuum in the fuel filler unit.

[0108] According to an embodiment, the evaporative emission system includes a fuel tank pressure sensor (FTPT) configured to sense the pressure of the evaporative emission system.

[0109] According to an embodiment, the door seal passes the diagnosis in response to sensing only one pressure inflection point during the diagnosis.

[0110] According to one embodiment, the instruction enables the controller to indicate that the leak is not due to the door seal.

[0111] According to an embodiment, the door seal fails the diagnosis in response to sensing multiple pressure inflection points during the diagnosis.

[0112] According to an embodiment, the instruction enables the controller to indicate that the leak is due to the door seal and request cleaning or replacement of the door seal.

[0113] According to an embodiment, the evaporative emission system is sealed off from the atmosphere during the diagnosis and fluidly coupled to the intake manifold of the engine of the vehicle.

[0114] According to an embodiment, the baffle is actuated in response to the presence of a vacuum.

[0115] According to the present invention, a method includes: in response to a leak detected in an evaporative emission system of an engine; sealing off the evaporative emission system from the atmosphere; creating a vacuum in the evaporative emission system and in a capless fuel filling system including a capless unit; monitoring the pressure of the evaporative emission system; and determining the condition of a door seal of the capless unit based on the number of detected pressure inflection points.

[0116] In one aspect of the present invention, determining the condition of the door seal includes determining that the door seal is deteriorated in response to the number of detected pressure inflection points being greater than one.

[0117] In one aspect of the present invention, determining the condition of the door seal includes determining that the door seal is not deteriorated in response to the number of detected pressure inflection points being equal to one.

[0118] In one aspect of the present invention, the engine is on during the diagnosis.

[0119] In one aspect of the present invention, the method includes requesting maintenance of the door seal in response to determining that the condition of the door seal is deteriorated.

Claims

1. A method comprising: A door seal of a capless unit of a capless refueling system is diagnosed by creating a vacuum in the capless refueling system. 2 . The method of claim 1 , wherein generating the vacuum in the capless fuel supply system comprises fluidly coupling the capless fuel supply system to an intake manifold of an engine.

3. The method of claim 1 , wherein the diagnosing includes determining that the door seal is passed in response to sensing only one inflection point during the diagnosing, wherein the only one inflection point is based on a pressure of the capless refueling system sensed by a fuel tank pressure sensor (FTPT). 4 . The method of claim 3 , wherein the diagnosing includes determining that the door seal has failed in response to sensing a plurality of inflection points during the diagnosing.

5. The method of claim 1, wherein creating a vacuum in the capless refueling system comprises opening a damper in the capless unit. The method of claim 1 , wherein the diagnostic is initiated in response to the presence of a leak in an evaporative emissions system. 7 . The method of claim 6 , further comprising, in response to indicating by the diagnostic that the leak is not due to a degraded door seal.

8. A capless fuel supply system for a vehicle, comprising: a capless unit having a baffle and configured to receive a nozzle of a fuel dispensing device; as well as A controller comprising computer readable instructions that, when executed, enable the controller to: detecting the presence of a leak in an evaporative emissions system of the vehicle; and Diagnosing the door seal of the coverless unit is performed via creating a vacuum in the coverless unit. 9 . The capless refueling system of claim 8 , wherein the evaporative emissions system includes a fuel tank pressure sensor (FTPT) configured to sense pressure of the evaporative emissions system.

10. The capless refueling system of claim 9, wherein the door seal passes the diagnostic in response to sensing only one pressure inflection point during the diagnostic.

11. The capless refueling system of claim 10, wherein the instructions enable the controller to indicate that the leak is not due to the door seal.

12. The capless refueling system of claim 9 wherein said door seal fails said diagnostic in response to sensing a plurality of pressure inflection points during said diagnostic.

13. The capless refueling system of claim 12, wherein the instructions enable the controller to indicate that the leak is due to the door seal and to request cleaning or replacement of the door seal.

14. The capless refueling system of claim 8, wherein the evaporative emissions system is sealed from atmosphere during the diagnostic period and is fluidly coupled to an intake manifold of an engine of the vehicle.

15. The capless refueling system of claim 8, wherein the flap is actuated in response to the presence of a vacuum.

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