Method and system for diagnosing the position of active grille shutters of a vehicle

Abstract

The present invention relates to a method and system for diagnosing the position of an active grille shutter of a vehicle, and provides a method and system for determining the position of an active grille shutter (AGS) using a light sensor positioned behind the AGS. In one example, a method may include diagnosing the position of the active grille shutter (AGS) in response to the output of the light sensor positioned behind the AGS, and adjusting an engine operating parameter in response to the diagnosed position. Further, the AGS diagnosis may be performed in response to an indication that ambient light outside the vehicle exceeds a threshold level.

Description

Technical Field

[0001] The present invention generally relates to methods and systems for diagnosing an active grille shutter system of a vehicle using a light sensor. Background Art

[0002] Active grille shutters (AGS) can be integrated into vehicles to help meet increasingly stringent fuel economy standards. Active grille shutters (AGS) are typically located near the front grille of the vehicle and can be selectively adjusted to increase or decrease the amount of fresh air that enters the underhood area of ​​the vehicle through the grille. When starting a cold engine, the AGS can be closed and kept closed to reduce the transfer of cold air from outside the engine compartment and thereby increase engine temperature more quickly to reduce vehicle emissions and fuel consumption. At elevated engine temperatures, the grille shutters can be opened to increase the amount of cold air entering the engine compartment, thereby increasing engine cooling. At higher vehicle speeds, when supplemental cooling is unfavorable, the active grille shutters can automatically close to block airflow through the engine cooling system, thereby reducing vehicle drag and fuel consumption. In some AGS systems, a position feedback sensor coupled to the grille shutters can be used to control the AGS.

[0003] Because of the impact of the AGS system on engine cooling, and therefore engine performance, exhaust emissions, and efficiency, robust diagnostics are needed to easily identify potential degradation in the AGS system. The AGS system can have many degradation modes. In one example, the AGS may be stuck in a fixed position, causing the grille shutters to fail to automatically adjust in response to engine operating conditions. In other examples, the mechanical linkage between the AGS grille and the AGS motor may be damaged, or the AGS position sensor or motor itself may be degraded. Other attempts to address diagnosing AGS system degradation include monitoring the engine temperature response when adjusting the position of the active grille shutters. Farmer et al. provide an example method in U.S. Patent Application Publication 2013 / 0338870. Therein, Farmers describes a method for performing extended diagnosis of the AGS system in response to monitoring a mechanical fault status signal (e.g., a mechanically broken or stuck AGS) and an indication that the temperature near the grille shutters is outside a threshold.

[0004] The inventors herein have recognized potential problems with such systems. Namely, such systems cannot address degradation of AGS operation due to a faulty AGS position sensor. Since a functional AGS position sensor must be relied upon to indicate a mechanical fault to even initiate a diagnostic, the diagnostic itself is incomplete. Furthermore, when an AGS system sensor or degradation occurs, completely disabling the AGS system forgoes any fuel consumption reduction advantage that is retained by continuing to operate the AGS at its current capacity. Summary of the invention

[0005] A method that at least partially addresses the above issues includes a method that includes: diagnosing a position of an active grille shutter (AGS) in response to an output of a first light sensor located behind the AGS in a vehicle; and adjusting an engine operating parameter in response to the diagnosed position. In this way, in response to a change in light level behind the active grille shutter, it can be determined whether the grille shutter is adjusted as commanded.

[0006] In another example, a vehicle system may include active grille shutters located at a front end of the vehicle; a light sensor located within the vehicle, behind and proximate to the AGS; and a controller including non-transitory instructions stored in a memory for: monitoring the output of the light sensor when the AGS is commanded to an open position and then to a closed position; diagnosing a position of the AGS in response to the monitored output of the light sensor relative to a threshold; and adjusting an engine operating parameter in response to the diagnosed position.

[0007] Thus, by utilizing the optical sensor behind the AGS to diagnose the position of the active grille shutters, degradation patterns of the AGS can be determined. These degradation patterns may include, but are not limited to, mechanical degradation of the AGS system, which may include degradation of the AGS motor, a stuck or damaged grille shutter, or degradation of the mechanical linkage between the AGS motor and the grille shutters. Additional degradation patterns that may be identified include a degraded AGS position sensor, if the AGS system is equipped with an AGS position sensor. The technical result of using an optical sensor to indicate degradation of the AGS system is that partial AGS degradation can be inferred, where the AGS can still be adjusted to a limited capacity. As a result, operation of the AGS can continue, albeit at a limited capacity, so that the advantage of reduced fuel consumption can be maximized. Further, it is more reliable to infer the AGS position by monitoring ambient temperature changes and engine temperature changes through an optical sensor relative to the inferred AGS position, because the engine temperature may not respond immediately to changes in the AGS position, and the engine temperature may change for a variety of reasons. As a result, by utilizing the output of the light sensor while commanding the AGS to different positions, the position of the AGS can be more accurately diagnosed and the user can be notified if the AGS system needs maintenance or replacement. The above and other advantages and features of the present invention will become apparent from the following detailed description when understood alone or in conjunction with the accompanying drawings.

[0008] It should be understood that the above summary is provided to introduce a selection of concepts further described in the detailed description in a simplified form. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the appended claims. Furthermore, the claimed subject matter is not limited to implementations that address any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 A schematic diagram of a vehicle system including active grille shutters (AGS) and an engine is shown.

[0010] Figure 2 Show Figure 1 Schematic diagram of a portion of a vehicle including active grille shutters, radiator and engine.

[0011] Figure 3 Show Figure 2 Schematic diagram of the various blade positions of the active grille shutter system.

[0012] Figure 4 An exemplary routine is shown that may be implemented to operate and diagnose an AGS system based on light indications proximate to the AGS.

[0013] Figure 5Predictive operation of an engine according to the present disclosure is shown, including controlling the AGS in response to engine operating conditions and AGS diagnostics. DETAILED DESCRIPTION

[0014] The following description relates to a device for operatively coupling to a device included in a vehicle (such as Figure 1 The active grille shutters (AGS) of an engine in a vehicle system (shown in FIG. 1 ) are provided. The active grille shutters may be positioned in a grille at a front end of a vehicle, wherein one or more light sensors are positioned behind the AGS to monitor the amount of ambient light entering through the active grille shutters from the front of the vehicle, such as Figure 2 The percentage opening of the AGS can be adjusted based on engine operating conditions to increase or decrease cooling airflow to the engine. Specifically, the engine controller can command the active grille shutters to assume one or more positions relative to the opening angle of the AGS, such as Figure 3 . When the active grille shutters are adjusted to the fully open position, an increased amount of ambient light may enter through the grille shutters and strike the sensor, causing an increased response or output of the light sensor behind the AGS. Likewise, when the active grille shutters are adjusted to the fully closed position, a decreased amount of ambient light may enter through the grille shutters and strike the sensor, causing a decreased response of the light sensor behind the AGS. By monitoring the response of the light sensor located behind the AGS, the degree of opening of the AGS may be inferred. Figure 4 A method for operating an AGS system and performing AGS diagnostics using a light sensor located behind the AGS is shown, and Figure 5 Shown according to Figure 4 An exemplary timeline of a routine for operating vehicle systems using the AGS system.

[0015] Now go to Figure 1 , which shows a schematic diagram of an exemplary vehicle 102 including an engine system 100 and an AGS system 110. The engine system 100 may be included in a vehicle such as a road vehicle, as well as in other types of vehicles. Although example applications of the engine system 100 will be described with reference to a vehicle, it should be understood that various types of engines and vehicle propulsion systems may be used, including passenger cars, trucks, etc. The engine system 100 may include an internal combustion engine or a diesel engine.

[0016] In some examples, the vehicle 102 may be a hybrid vehicle with multiple torque sources available for one or more vehicle wheels 76. In other examples, the vehicle 102 is a conventional vehicle with only an engine or an electric vehicle with only (one or more) motors. In the example shown, the vehicle 102 includes an engine 10 and a motor 72. The motor 72 may be a motor or a motor / generator. When one or more clutches 73 are engaged, the crankshaft 140 of the engine 10 and the motor 72 are connected to the vehicle wheels 76 via a transmission 74. In the depicted example, the first clutch 73 is disposed between the crankshaft 140 and the motor 72, and the second clutch 73 is disposed between the motor 72 and the transmission 74. The controller 12 may send a signal to the actuator of each clutch 73 to engage or disengage the clutch so as to connect or disconnect the crankshaft 140 with the motor 72 and the components connected thereto, and / or connect or disconnect the motor 72 with the transmission 74 and the components connected thereto. The transmission 74 may be a gearbox, a planetary gear system, or other types of transmissions. The powertrain may be configured in various ways, including being configured as a parallel, series, or series-parallel hybrid vehicle.

[0017] In the illustrated embodiment, the electric machine 72 receives power from a traction battery 75 to provide torque to vehicle wheels 76. The electric machine 72 may also operate as a generator to provide power to charge the battery 75, such as during braking operations. It should be appreciated that embodiments including the engine 10 without the electric machine 72, the traction battery 75 may be replaced by a start-ignition combustion (SLI) battery.

[0018] like Figure 1 As shown in the exemplary engine system 100 of FIG. 1 , the engine 10 is a supercharged engine coupled to a turbocharger 13 including a compressor 14 driven by a turbine 16. Specifically, fresh air is introduced into the engine 10 at the intake passage 42 via the air cleaner 11 and the compressor 14. The compressor may be a suitable intake compressor, such as a supercharger compressor driven by a motor or a drive shaft. In the engine system 100, the compressor 14 is shown as a turbocharger compressor mechanically coupled to the turbine 16 via a shaft 19, and the turbine 16 is driven by expanding the engine exhaust. In one embodiment, the compressor 14 and the turbine 16 may be coupled in a twin-scroll turbocharger. In another embodiment, the turbocharger 13 may be a variable geometry turbocharger (VGT), in which the turbine geometry is actively changed according to the engine speed and other operating conditions.

[0019] like Figure 1As shown, compressor 14 is coupled to throttle 20 through charge air cooler (CAC) 18. For example, the CAC may be an air-to-air or air-to-water heat exchanger. Throttle 20 is coupled to engine intake manifold 22. Hot compressed air charge from compressor 14 enters the inlet of CAC 18, cools as it travels through the CAC, and then exits to pass through throttle 20 to engine intake manifold 22. Ambient airflow 116 from outside the vehicle may enter engine 10 through vehicle grille 112 at the front end of the vehicle and pass through CAC 18 to help cool the charge air. When ambient air temperature decreases, or during humid or rainy weather conditions where the charge air is cooled below the water dew point, condensate may form and accumulate in CAC 18. When the charge air includes recirculated exhaust gas, the condensate may become acidic and corrode the CAC housing. In the case of a water-to-air cooler, corrosion may result in leaks between the air charge, the atmosphere, and possibly the coolant. Additionally, condensate may collect at the bottom of the CAC 18 and then be immediately drawn into the engine during acceleration (or tip-in), thereby increasing the likelihood of engine stall. In one example, cooling of the ambient airflow traveling to the CAC 18 may be controlled by the AGS system 110 such that condensate formation and engine stall events are reduced. Specifically, the AGS system 110 may include one or more active grille shutters 114 (also referred to herein as shutters or grille shutters) that may be selectively controlled in response to operating conditions including, but not limited to, engine coolant temperature and vehicle speed. In some embodiments, the position of the active grille shutters may be monitored by one or more optional AGS position sensors 115. Figure 1 In the illustrated embodiment, the AGS system also includes a light sensor 113 located behind the grille shutters. It should be appreciated that the light sensor 113 is located behind the grille shutters of the vehicle so that it can monitor changes in the amount of light entering through the grille shutters from the front of the vehicle. In this manner, when the grille shutters are adjusted to a fully open position, the light sensor 113 may be exposed to only an upper threshold level of ambient light. When the opening of the grille shutters is reduced, the amount of ambient light entering through the grille shutters may be reduced, thereby reducing the amount of light striking the light sensor 113. Specifically, the light sensor 113 may be located under the hood of the vehicle (not shown) and inside the engine compartment.

[0020] In some non-limiting examples, the opening angle of the AGS may be adjusted to control condensate formation at the CAC 18 as well as engine cooling and / or vehicle drag. In one example, the opening angle of the AGS may be decreased to reduce the amount of cool, moist air that enters the grille and passes through the CAC. As a result, the outlet temperature of the CAC 18 may be increased, thereby reducing the likelihood of condensate formation. In another example, the opening angle of the grille shutters 114 may be increased to increase the amount of cool air allowed to enter through the vehicle grille 112 and pass through the radiator 80. As a result, increased engine cooling may be achieved.

[0021] exist Figure 1 In the illustrated embodiment, the pressure of the air charge within the engine intake manifold 22 is sensed by a manifold air pressure (MAP) sensor 24, and the boost pressure is sensed by a boost pressure sensor 124. A compressor bypass valve (not shown) may be coupled in series between the inlet and outlet of the compressor 14. The compressor bypass valve may be a normally closed valve that is configured to open under selected operating conditions to relieve excess boost pressure. For example, the compressor bypass valve may be opened during conditions that reduce engine speed to avoid compressor surge.

[0022] The engine intake manifold 22 is coupled to a series of combustion chambers (e.g., cylinder 31) through a series of intake valves (not shown). In addition, the fuel flow can be delivered to the cylinder 31 by one or more fuel injectors 66 in a configuration known as direct injection. In some examples, the engine 10 may additionally or alternatively include a fuel injector located in the intake manifold 22, which has a configuration generally known as port injection. The combustion chamber 31 is further coupled to the exhaust manifold 36 through a series of exhaust valves (not shown). In the depicted embodiment, a single exhaust manifold 36 is shown. However, in other embodiments, the exhaust manifold 36 may include multiple exhaust manifold sections. A configuration with multiple exhaust manifold sections can enable outflows from different combustion chambers to be directed to different locations in the engine system. The universal or wide-range exhaust gas oxygen (UEGO) sensor 126 is shown as coupled to the exhaust manifold 36 upstream of the turbine 16. Alternatively, a two-state exhaust gas oxygen sensor may replace the UEGO sensor 126.

[0023] like Figure 1 As shown, exhaust gas from one or more exhaust manifold sections is directed to turbine 16 to drive the turbine. When reduced turbine torque is desired, some exhaust gas may be directed instead through a wastegate (not shown), bypassing the turbine. The combined flow from the turbine and the wastegate then flows through emission control device 70. Typically, emission control device 70 may include multiple emission control devices, such as one or more exhaust aftertreatment catalysts, which are configured to catalytically treat the exhaust flow and thereby reduce the amount of one or more substances in the exhaust flow.

[0024] All or a portion of the treated exhaust gas from the emission control device 70 may be released into the atmosphere via the exhaust conduit 35. However, depending on operating conditions, some of the exhaust gas may be diverted to the EGR passage 51 via the EGR cooler 50 and the EGR valve 52 to the inlet of the compressor 14. In this way, the compressor is configured to allow exhaust gas to be drawn from the downstream of the turbine 16. The EGR valve 52 may be opened to allow a controlled amount of cooled exhaust gas to reach the compressor inlet to obtain desired combustion and emission control performance. In this way, the engine system 100 is adapted to provide external low-pressure (LP) EGR. In addition to the relatively long LP EGR flow path in the engine system 100, the rotation of the compressor 14 may also provide excellent homogenization of the exhaust gas into the intake air charge. Further, the setting of the EGR take-off and mixing point may provide more efficient exhaust cooling for increased available EGR mass and enhanced performance. In other embodiments, the EGR system may be a high-pressure (HP) EGR system in which the EGR passage 51 is connected from the upstream of the turbine 16 to the downstream of the compressor 14.

[0025] The motor vehicle 102 further includes a cooling system 104 that circulates coolant through the internal combustion engine 10 to absorb waste heat and distributes the heated coolant to the radiator 80 and / or the heater core 90 via coolant lines 82 and 84, respectively. Figure 1 Cooling system 104 is shown coupled to engine 10 and circulates engine coolant from engine 10 to radiator 80 via engine driven water pump 86 and back to engine 10 via coolant line 82. Engine driven water pump 86 may be coupled to the engine via front end accessory drive (FEAD) 88 and rotated in proportion to engine speed via a belt, chain, etc. (not shown). Specifically, engine driven water pump 86 circulates coolant through passages in the engine block, engine head, etc. to absorb engine heat, which is then transferred to ambient air via radiator 80. In examples where engine driven water pump 86 is a centrifugal pump, the pressure generated at the outlet of the engine driven water pump (and the resulting flow rate) may be proportional to the crankshaft speed, in Figure 1 In one example, it is proportional to engine speed. In another example, a motor-controlled pump that can be adjusted independently of engine rotation can be used. The temperature of the coolant (e.g., engine coolant temperature, ECT) can be regulated by a thermostatic valve 38 located in the coolant line 82, which can remain closed until the coolant reaches a threshold temperature.

[0026] The engine system 100 may include an electric fan 92 for directing cooling airflow toward the CAC 18, the engine cooling system 104, or other engine system components. In some embodiments, the electric fan 92 may be an engine cooling fan. The engine cooling fan may be coupled to the radiator 80 to maintain airflow through the radiator 80 when the vehicle 102 is moving slowly or stopped while the engine is running. The fan rotation speed or direction may be controlled by the controller 12. In one example, the engine cooling fan may also direct cooling airflow toward the CAC 18. Alternatively, the electric fan 92 may be coupled to the engine FEAD 88 and driven by the engine crankshaft 140. In other embodiments, the electric fan 92 may serve as a dedicated CAC fan. In this embodiment, the electric fan 92 may be coupled to the CAC 18 or placed in a position to direct airflow directly toward the CAC 18. In yet another embodiment, there may be two or more electric fans 92. For example, one electric fan may be coupled to the radiator (as shown) for engine cooling, while another electric fan may be coupled elsewhere to direct cooling air directly toward CAC 18. In this example, two or more electric fans 92 may be individually controlled (e.g., at different rotational speeds) to provide cooling for their respective components.

[0027] As described above, coolant may flow through coolant line 82 and / or through coolant line 84 to heater core 90 where heat may be transferred to passenger compartment 106 via air ducts (not shown) and the coolant flows back to engine 10. In some examples, engine driven water pump 86 may be operated to circulate coolant through coolant lines 82 and 84.

[0028] Figure 1 A control system 28 is further shown. The control system 28 may be communicatively coupled to the various components of the engine system 100 to perform the control routines and actions described herein. Figure 1As shown, the control system 28 may include an electronic digital controller 12. The controller 12 may be a microcomputer including a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, a random access memory (RAM), a keyless memory (KAM), and a data bus. As depicted, the controller 12 may receive inputs from a plurality of sensors 30, which may include user inputs and / or sensor input data (e.g., transmission gear position, accelerator pedal position input, brake pedal input, transmission selector position, vehicle speed, engine speed, mass airflow through the engine, boost pressure, ambient temperature, ambient humidity, intake air temperature, fan speed, ambient light), inputs from cooling system sensors (e.g., engine coolant temperature, fan speed, passenger compartment temperature, ambient humidity), inputs from CAC 18 sensors (e.g., CAC inlet air temperature and pressure, CAC outlet air temperature and pressure), inputs from one or more optional AGS position sensors 115, inputs from the AGS light sensor 113, and inputs from other vehicle sensors. Additionally, the controller 12 may receive data from the GPS 34 and / or the onboard communications and entertainment system 26 of the vehicle 102 .

[0029] The in-vehicle communication and entertainment system 26 can communicate with the wireless communication device 40 via various wireless protocols such as wireless networks, cell tower transmissions, and / or combinations thereof. The data obtained from the in-vehicle communication and entertainment system 26 can include real-time and forecasted weather conditions. Weather conditions such as temperature, cloud cover, precipitation (e.g., rain, snow, hail, etc.) and humidity can be obtained through various wireless communication device applications and weather forecast websites. The data obtained from the in-vehicle communication and entertainment system 26 can include current and forecasted weather conditions for the current location, as well as future locations along the planned driving route. In one embodiment, in the case where the in-vehicle communication and entertainment system 26 includes a GPS 34, the current and future weather data can be associated with the current and future driving routes displayed on the GPS 34. In an alternative embodiment, where the vehicle system includes a dedicated GPS 34, each of the GPS 34 and the in-vehicle communication and entertainment system 26 can communicate with the wireless communication device 40 and communicate with each other to communicate the current and future weather data with the current and future driving routes. In one example, the in-vehicle and communication entertainment system 26 can access various weather maps stored on the Internet or other cloud computing systems. For example, the stored weather maps may include rain, humidity, precipitation, ambient light information, and / or temperature information provided as contour maps. In one example, the wireless communication device 40 may relay real-time weather data to the onboard communications and entertainment system 26 and / or GPS 34, which is then relayed to the controller 12. The controller 12 may compare the received weather data (which may include humidity data) to a threshold value and determine appropriate engine operating parameter adjustments. In one example, these adjustments may include adjusting the AGS system 110. For example, if the humidity is greater than a defined threshold, one or more blades of the AGS may be closed.

[0030] Additionally, the controller 12 may communicate with various actuators 32 , which may include engine actuators (e.g., fuel injectors, electronically controlled air intake throttle plates, spark plugs), cooling system actuators (e.g., air handling vents and / or reversing valves in a passenger cabin climate control system), AGS system actuators (e.g., AGS vanes, AGS motors), etc. In some examples, the storage medium of the controller 12 may be programmed with computer-readable data representing instructions that may be executed by a processor to perform the method described below as well as other variations that are anticipated but not specifically listed.

[0031] As described herein, the amount of waste heat transferred from engine 10 to coolant may vary based on vehicle operating conditions, thereby affecting the amount of heat transferred to air flowing through engine system 100. For example, as engine output torque or fuel flow decreases, the amount of waste heat generated may decrease proportionally.

[0032] The motor vehicle 102 further includes a vehicle grille 112 that provides an opening (e.g., a grille opening, a bumper opening, etc.) for receiving an ambient airflow 116 (from outside the vehicle) through or near the front end of the vehicle and into the engine compartment. As previously described, the entry of the ambient airflow 116 into the engine compartment can be controlled by the AGS system 110. Heat can be transferred to the ambient airflow 116 via the radiator 80, the electric fan 92, and other components to keep the engine 10 and / or the transmission cool. Further, the ambient airflow 116 can remove heat from the vehicle air conditioning system and can improve the performance of a turbocharged / supercharged engine equipped with a CAC 18, which reduces the temperature of the air entering the intake manifold / engine. In one example, the electric fan 92 can be adjusted to further increase or decrease the airflow to the engine components. In another example, a dedicated CAC fan can be included in the engine system 100 for increasing or decreasing the airflow to the CAC 18.

[0033] Now go to Figure 2 , exemplary embodiment 200 shows Figure 1 1 is a partial schematic diagram of a vehicle 102. Included are CAC 18, radiator 80, electric fan 92, engine 10, AGS system 110, and associated ambient airflow 116 therethrough. These and other vehicle and engine components may be located beneath the vehicle hood 208. When the vehicle is on level ground, the underside location may include within the vehicle's drivetrain compartment, vertically below the hood, but above the bottom of the vehicle and / or within the vehicle's outer skin / body. Other under-hood components (such as the fuel system, batteries, etc.) may also benefit from the cooling airflow. Thus, the AGS system 110 may assist the cooling system 104 ( Figure 1 ).exist Figure 2 In the example shown in FIG. 1 , the AGS system 110 may be a dual active grille shutter system including two sets of one or more grille shutters 114 , each set of grille shutters being configured to adjust the amount of airflow received through the vehicle grille 112 , such as Figure 1 In another example, the AGS system 110 may be an active grille shutter system including a single set of one or more grille shutters 114 , or more than two sets of one or more grille shutters 114 .

[0034] For example, grille shutters 114 may cover a front area of ​​the vehicle spanning from just below hood 208 to the bottom of the bumper. By covering the front end of the vehicle, drag may be reduced and the ingress of external cooling air to radiator 80 and CAC 18 may be reduced. In some embodiments, all grille shutters 114 may be moved in coordination by controller 12. In other embodiments, grille shutters 114 may be grouped, and controller 12 may independently adjust the opening / closing of each group of grille shutters 114. For example, a first group of grille shutters 204 may be positioned in front of radiator 80, and a second group of grille shutters 206 may be positioned in front of CAC 18.

[0035] The AGS system may optionally include one or more AGS position sensors 115 positioned proximate to the grille shutters 114. In an example where an AGS position sensor is optionally included, at least one AGS position sensor 115 may be positioned proximate to each set of grille shutters 114. For example, at least one AGS position sensor 115 may be positioned proximate to each of the first set of grille shutters 204 and the second set of grille shutters 206. As another example, the AGS position sensor 115 may be arranged proximate to the AGS motor 202. In one example, the AGS position sensor 115 may be a Hall effect sensor. The Hall effect sensor may include a transducer that changes its output voltage in response to a magnetic field, such as a magnetic field generated by rotating the AGS motor 202. The AGS position sensor 115 may be calibrated in response to a key-on engine state. For example, in response to a key-off engine state, the AGS may be automatically moved to a fully open position by a controller. Thus, at key-on, the AGS position sensor may be calibrated to correspond to the fully open position, and subsequent control actions to change the AGS position via the AGS motor 202 may be performed relative to the key-on calibrated position.

[0036] The AGS system may also include one or more first light sensors (e.g., AGS light sensor 113) located near grille shutters 114 inside the vehicle interior and the engine compartment area (also referred to as the engine compartment). Specifically, the AGS light sensor 113 may be located behind the grille shutters. In other words, the AGS light sensor 113 may be placed between the grille shutters 114 and the engine 10, on the side of the grille shutters away from the front of the vehicle 102. In one example, at least one AGS light sensor 113 may be located near each group of grille shutters. For example, at least one AGS light sensor 113 may be positioned adjacent to each of the first group of grille shutters 204 and the second group of grille shutters 206. In one example, the AGS light sensor 113 may be any type of suitable light sensor, including but not limited to a photodiode, a photoelectric sensor, and a solar cell. It should be understood that the AGS light sensor 113 may be calibrated in response to the key-on state. As previously described, in response to a key-off engine state, the AGS can be automatically moved to a fully open position by a controller, and then in response to a key-on engine state, the AGS light sensor can be calibrated to correspond to a light indication of the fully open position, and subsequent control actions to change the AGS position via the AGS motor 202 can be performed relative to the key-on calibrated light indication.

[0037] The vehicle 102 may also include one or more second light sensors 213. In one example, the second light sensor 213 may include a light sensor located near a rearview mirror, such as a light sensor for controlling the automatic dimming of the rearview mirror. In other examples, the second light sensor may include a light sensor located on the vehicle dashboard and / or adjacent to the vehicle headlights, such as a light sensor for controlling the power on / off and automatic dimming of the vehicle headlights. The second light sensor 213 is positioned so that it can be exposed to ambient light conditions outside the vehicle 102, while the first light sensor 113 can be exposed to ambient light conditions only when the AGS is not in a fully closed position that blocks light from entering the grille. For example, when the grille is adjusted to a partially or fully open position, ambient light and air can enter through the opening created between the grilles. When the AGS is fully closed, ambient light can be blocked from entering the engine compartment area behind the AGS, and thus the light output of the first light sensor 113 can be a threshold amount lower than the light output of the second light sensor 213. As the AGS are opened to a greater extent (e.g., as they approach a fully open position), the level or intensity of ambient light that enters the in-engine compartment area of ​​the vehicle (and strikes and is detected by first light sensor 113) may increase. When the AGS is fully opened so that a maximum amount of ambient light can enter the in-engine compartment area and strike first light sensor 113, the light output of first light sensor 113 may be closest to the light output of second light sensor 213.

[0038] like Figure 2 As shown, first set of grille shutters 204 may be vertically positioned above second set of grille shutters 206 relative to the surface on which vehicle 102 is seated. As such, first set of grille shutters 204 may be referred to as upper grille shutters and second set of grille shutters 206 may be referred to as lower grille shutters. The amount of opening of first set of grille shutters 204 may control the amount of ambient airflow 116 directed to radiator 80, and the amount of opening of second set of grille shutters 206 may control the amount of ambient airflow directed to CAC 18. As such, upper grille shutters may largely affect vehicle drag and engine cooling, while lower grille shutters may largely affect CAC cooling. However, it should be understood that one or more sets of grille shutters may also be arranged horizontally side-by-side, rather than vertically above or below another set of grille shutters.

[0039] In some examples, each set of grille shutters 114 may include the same number of grille shutters 114, while in other examples, one set of grille shutters may include a greater number of grille shutters than the other set. In one embodiment, the first set of grille shutters 204 may include a plurality of grille shutters, while the second set of grille shutters 206 includes one grille shutter. In an alternative embodiment, the first set of grille shutters may include one grille shutter, while the second set of grille shutters may include more than one grille shutter. In an alternative embodiment, all of the grille shutters 114 may be included in a single set of grille shutters, and the amount of opening of the single set of grille shutters 114 may affect vehicle drag, engine cooling, and CAC cooling.

[0040] The grille shutters 114 can be positioned between a fully open position and a fully closed position, and can be maintained in the fully open position, the fully closed position, or a plurality of intermediate positions therebetween. In other words, the opening of the grille shutters 114 can be adjusted so that the grille shutters 114 are partially open, partially closed, or cycled between the fully open position and the fully closed position to provide airflow for cooling engine system components. The fully open position can be referred to as the maximum opening amount (or maximum percentage opening) position, and the fully closed position can be referred to as the maximum closing amount (or maximum percentage closing) position. The opening amount of the grille shutters 114 or a group of grille shutters (e.g., the first group of grille shutters 204 or the second group of grille shutters 206) can be represented by a percentage (e.g., a percentage opening). For example, when the AGS is between the open position and the closed position, the AGS can be 50% open (or 50% closed). When the AGS is opened to the maximum percentage opening (e.g., the upper threshold amount of the opening), the AGS can be 100% open.

[0041] The grille shutters 114 (eg, upper grille shutters) may be actuated by an AGS motor 202. The AGS motor 202 may be operably coupled to the control system 28, such as Figure 1 As shown. As an example, the controller 12 may be communicatively connected to the AGS system 110 and may have executable instructions stored thereon to adjust the opening of the grille shutters 114 via the AGS motor 202. The controller 12 may send signals for adjusting the AGS system 110 to the AGS motor 202. These signals may include commands to increase or decrease the opening of the upper grille shutters and / or the lower grille shutters. As an example, the controller 12 may output a voltage to the AGS motor corresponding to fully opening, fully closing, or partially opening the grille shutters 114. For example, the controller 12 may output a voltage to the AGS motor 202 to open the upper grille shutters to 30% open. Accordingly, the AGS motor 202 may draw an AGS motor current when the grille shutters 114 are fully opened, fully closed, or partially opened. In addition, the controller 12 may detect or measure the AGS motor current to determine the AGS position. In addition, when the AGS motor is rotated in a first direction (e.g., corresponding to opening the AGS grille shutters), the output voltage of the AGS motor and the AGS motor current may have a first polarity, and when the AGS motor is rotated in a second direction opposite to the first direction (e.g., corresponding to closing the AGS grille shutters), the output voltage of the AGS motor and the AGS motor current may have a second polarity opposite to the first polarity.

[0042] The AGS motor 202 may be coupled to one or more grille shutters 114. For example, the AGS motor 202 may be coupled to a first grille shutter 114 that is mechanically linked to the remaining grille shutters 114. In another example, the AGS motor 202 may be coupled to each grille shutter 114 or each group of grille shutters. Further, in some examples, the AGS system 110 may include more than one motor for controlling more than one group or more than one individual grille shutter. For example, the AGS system includes an intelligent motor that communicates with the AGS system 110 on a multiplexed bus. Figure 1 The AGS motor may include an output shaft connected to the AGS housing (not shown) and connected to one of a plurality of movable blades that are linked together to form a group. When the AGS motor output shaft moves, it moves the attached blade, which causes the other blades in the group to move together. In some examples, a mechanical linkage (not shown) that may include gears may be provided between the blade sets in a master / slave relationship.

[0043] Now go to Figure 3, illustrates exemplary grille shutter positions for a single blade (eg, a single grille shutter 114 ). Specifically, schematic diagram 300 illustrates grille shutters 114 (eg, Figure 2 1. A side view of grille shutters 114 is shown. Grille shutters 114 are rotatable about a second axis 308 located on the central rotational axis of the blades. Grille shutters 114 are rotatable between a fully closed position and a fully open position defined by a vertical axis 310 and a lateral axis 312 of the AGS, respectively.

[0044] A first grille shutter position is shown at 302. The first grille shutter position is a fully closed position in which the AGS is fully closed, thereby preventing airflow and / or ambient light 116 from entering the vehicle through the grille. A light sensor 113 is located inside the engine compartment area of ​​the vehicle and on an opposite side of the grille shutter 114 because incoming airflow and ambient light 116 (from outside the vehicle) can produce a sensor output that indicates an amount of ambient light passing through the grille shutter. When the grille shutters are fully closed, the amount of light entering through the grille shutters will be less than the amount of light entering through the grille shutters when the grille shutters are partially or fully open. The percentage opening when the AGS is fully closed may be 0%, and the percentage closing when the AGS is fully closed may be 100%. When the AGS is fully closed, the amount of ambient light entering through the grille shutter opening will be less than the amount of ambient light entering through the grille shutter opening when the grille shutters are fully open. At position 302 , a vane axis 318 (shown in position 304 ) of grille shutters 114 may be aligned with vertical axis 310 such that an angle between grille shutters 114 and vertical axis 310 may be approximately 0° (vane axis 318 as shown at 304 is parallel to vertical axis 310 ). This angle may be referred to as an opening angle. In other embodiments, the fully closed grille shutter position may be slightly greater than 0° (e.g., 5°) to allow for overlap of adjacent grille shutters.

[0045] In one example, upon reaching a fully closed position (e.g., a maximum percentage closed of 100% (and a percentage open of 0%)), the grille shutters 114 may contact the end stop 321. The end stop 321 may be coupled to a support structure (e.g., an outer frame) of the AGS system 110. For example, the end stop 321 may be positioned along a vertical axis 310 of at least one grille shutter 114 in a group of grille shutters. Thus, upon reaching a maximum percentage closed position of 100%, at least one grille shutter 114 in a group of grille shutters may contact the end stop 321.

[0046] A second grille shutter position is shown at 304. The second grille shutter position is an intermediate position between the fully open position and the fully closed position, in which the grille shutter 114 can be partially open (or partially closed). An opening angle 316 is defined between the vertical axis 310 of the grille shutter 114 and the blade axis 318. In one example, the opening angle 316 can be approximately 36°, so that the percentage opening of the AGS is approximately 40%. In another example, the opening angle can be approximately 9°, so that the percentage opening of the AGS is approximately 10%. In some cases, the controller can also determine the percentage closing of the AGS. For example, the percentage closing of the AGS can be calculated as 100 minus the percentage opening. In the example where the percentage opening is 40%, the percentage closing is 60%. The partially open grille shutter 114 allows ambient light and / or airflow 116 to flow around the blades, through the opening formed by the partially open grille shutter 114 and into the vehicle and toward the engine. The incoming ambient light can strike and trigger an electrical response from the light sensor 113. It will be appreciated that for constant ambient light conditions outside of the vehicle and grille shutters 114 (e.g., from the direction of ambient light and airflow 116), the response of light sensor 113 to grille shutter position 304 may be greater than the response of light sensor 113 to grille shutter position 302. Additionally, the response of light sensor 113 may be less than the response from second light sensor 213, such as Figure 2 shown.

[0047] A third exemplary grille shutter position is shown at 306 . The third grille shutter position is a fully open position, thereby allowing maximum ambient airflow and / or ambient light 116 to enter the vehicle and the engine compartment through the grille. Therefore, the fully open position may be referred to herein as maximum opening or maximum percentage opening. When the AGS is fully open, the opening angle 316 is approximately 90° (the blade axis 318 is parallel to the lateral axis 312 ) and the percentage opening is 100%. Similarly, ambient light and airflow 116 may pass through the grille shutters 114 relatively unimpeded, and the ambient light may impinge on and induce a response from the first light sensor 113 . It will be appreciated that for constant ambient light conditions external to the vehicle and grille shutters 114 (e.g., from the direction of the ambient light and airflow 116 ), the response of the light sensor 113 to the grille shutter position 306 may be greater than the response of the light sensor 113 to the grille shutter positions 304 and 302 . Further, the output from light sensor 113 for grille shutter position 306 may be closer to the output from second light sensor 213 (from active grille shutter position 304 or 302 ) than the output from active grille shutter position 304 or 302 . Figure 2). In one example, upon reaching a maximum percentage opening of 100% (and an opening angle of 90°), the grille shutters 114 may contact the end stop 320. The end stop 320 may be coupled to a support structure (e.g., an external frame) of the AGS system 110. For example, the end stop 320 may be positioned along a lateral axis of at least one grille shutter 114 in a group of grille shutters. In this way, at least one grille shutter 114 in a group of grille shutters may contact the end stop 320 upon reaching a maximum percentage opening of 100%.

[0048] In this manner, the grille shutter blades 114 of the AGS system 110 may be adjusted to a plurality of positions between 0% open (a fully closed position) and 100% open (a maximum percentage opening or fully open position). Figure 1 The illustrated AGS motor may actuate the grille shutters 114 to different positions based on a commanded grille shutter position via a mechanical linkage (not shown).

[0049] During normal operation, the AGS may be fully open when the engine is off. When starting a cold engine, the controller 12 may command the AGS to remain closed for a period of time to allow the engine to warm up and reach an efficient operating temperature more quickly, which may help reduce fuel consumption and engine emissions. When the engine is cold and the engine load is low, the controller 12 may also command the AGS to close to block airflow through the grille, which may help reduce vehicle drag and fuel consumption. The AGS may also be closed at higher vehicle speeds, particularly during constant cruising speeds and low engine loads, to reduce fuel consumption. When the engine temperature decreases, the AGS may be commanded open by the controller 12. AGS control may also be used to assist in controlling engine coolant temperature, condensate formation, HVAC performance, and exhaust emissions in response to one or more of vehicle speed, engine coolant temperature, and engine load.

[0050] During vehicle operation, AGS degradation can occur in various ways. Figure 1 As described above, the AGS grille shutters 114 may become stuck in one position (e.g., in a stationary position despite being actuated by the motor) or damaged due to mechanical degradation of parts of the AGS system or foreign debris entering the front vehicle grille 112. The mechanical linkage between the AGS motor 202 and the grille shutters 114 may degrade or wear out or break down over time. The AGS motor 202 may also experience mechanical degradation or may continue to function without a load in the presence of a degraded mechanical linkage with the grille shutters 114.

[0051] By positioning the light sensor behind the active grille shutters, the amount of ambient light entering the engine compartment through the openings between the grille shutters (also more simply referred to herein as "through the grille shutters") can be monitored. In one example, in response to a light sensor located behind the hood of the vehicle (e.g., Figure 2 The output of the first light sensor 113 under the hood 208 ) behind the active grille shutters 114 can diagnose (eg, determine) the position (eg, opening degree) of the AGS.

[0052] As described above, the AGS system 110 may optionally include an AGS position sensor 115. As an example, the AGS position sensor 115 may include a Hall effect sensor and may be used to determine the AGS position in the AGS position feedback control strategy. If the AGS position sensor loses functionality, the AGS feedback control strategy may no longer determine the grille shutter position directly from the AGS position sensor. It should be understood that in an AGS system embodiment including an AGS position sensor, in addition to AGS mechanical type degradation, the AGS position sensor 115 may be degraded or may fail due to damage or contamination of the environment. Other embodiments may include a temperature sensor close to the AGS system to try to determine whether the active grille shutter has taken a command position and identify potential degradation in response to the temperature sensor output. It should be understood that the AGS light sensor located behind the AGS can be further used to confirm the operation of other AGS system sensors (such as AGS position sensors or AGS temperature sensors) or suggest degradation. When these AGS sensors are degraded, the ability to infer or determine the AGS position using alternative methods (e.g., using AGS position or temperature sensors instead) can allow at least part of the AGS to continue to operate. For example, if the AGS can still be fully opened but not fully closed, at least a portion of the reduction in fuel economy imparted by the operation of the AGS system 110 can be retained. Conversely, in the case of a purely mechanical AGS degradation, including the AGS being stuck in a certain position and unable to be adjusted, engine parameters can be adjusted to mitigate the potentially harmful effects of a stuck AGS system. In one example, in response to an AGS stuck in a closed position, the cooling fan can be started earlier than otherwise in order to provide adequate cooling for the engine. In another example, the HVAC output can be reduced in order to reduce the load on the engine, thereby also reducing the cooling requirements of the engine. Further examples can include moving the AGS to a default position and disabling further adjustment of the AGS in response to engine operating conditions. In this way, engine overheating can be avoided, and / or the likelihood of AGS motor burnout and / or other AGS system damage can be reduced.

[0053] In this way, a system for a vehicle may include an active grille shutter (AGS) located at a front end of the vehicle; a first light sensor located within the vehicle and behind and proximate to the AGS; and a controller including non-transitory instructions stored in a memory, the instructions being used to: monitor the output of the light sensor when the AGS is commanded to an open position and then to a closed position; diagnose a position of the AGS in response to the monitored output of the light sensor relative to a threshold; and adjust an engine operating parameter in response to the diagnosed position.

[0054] Now go to Figure 4 , which shows the operation of an AGS system (such as Figure 1-Figure 2 ) including a method for diagnosing a position of the AGS. An example of a diagnostic position of the AGS includes a position different from a commanded position (e.g., degraded). Routine 400 also includes responding to a diagnostic position of the AGS, including degradation, based on a light indication proximate to the AGS. In other words, routine 400 may include performing a type of rationality test on the AGS system to determine whether active grille shutters of the AGS system are misplaced (e.g., in a position different from a commanded position) or stuck in a position, and / or whether one or more components of the AGS system are degraded. The diagnostic position of the AGS may be determined by a controller (e.g., Figure 1 The controller 12) is based on instructions stored in the memory of the controller and in conjunction with instructions from the engine system (e.g., Figure 1 of the engine system 100) (such as the above referenced Figure 1 Instructions for performing routine 400 and the remainder of the methods included herein may be implemented using signals received from sensors (described herein) of the engine system. According to the methods described below, the controller may employ engine actuators of the engine system to adjust engine operation.

[0055] Routine 400 begins at 402, where the routine includes estimating and / or measuring engine operating conditions, which may include engine speed (Ne), driver torque demand (Tq), engine coolant temperature (ECT), barometric pressure (BP), engine boost, vehicle speed (VS), ambient light conditions (e.g., as determined by, for example, Figure 2 ), ambient temperature, and ambient humidity. The routine then continues to 404, where the routine includes adjusting the active grille shutters based on engine operating conditions (e.g., Figure 2 Adjusting the active grille shutters 114 may include a vehicle controller (e.g., Figure 1 The controller 12) is coupled to the motor ( Figure 2AGS motor 202 of the active grille shutter sends a signal (via a mechanical linkage, in one example) to adjust the degree of opening (e.g., opening angle or percentage opening) of the active grille shutters. In one example, in response to starting a cold engine (e.g., when the engine coolant temperature (ECT) is below a threshold value, Figure 1 10), the active grille shutters can be adjusted to a fully closed position, thereby blocking ambient air and light from entering the engine compartment area of ​​the vehicle to reduce the ingress of cold air and accelerate rapid warming of the engine. In another example, in response to the engine coolant temperature (ECT) being above a threshold, the controller can send a signal to the AGS motor to actuate a mechanical linkage coupled to the AGS to increase the opening angle of the active grille shutters to increase the amount of air entering the grille, thereby helping to increase engine cooling. In this way, adjustment of the AGS can be used to actively control engine coolant temperature and increase engine performance and increase fuel efficiency. In addition, the AGS can be selectively controlled in response to indications of ambient humidity and other engine parameters from a humidity sensor to alleviate the charge air cooler (e.g., Figure 1 and Figure 2 Condensate accumulation in the CAC 18 of the vehicle. In a further example, in response to the vehicle speed being above a threshold and the engine coolant temperature being below a threshold, the vehicle controller may send a signal to an AGS motor coupled to the active grille shutters to adjust the degree of opening of the active grille shutters to a fully closed position. In this manner, the likelihood of engine overcooling may be reduced by reducing the amount of intake air entering through the grille. Additionally, by reducing the amount of intake air entering through the grille, vehicle drag may also be reduced, which may result in increased fuel economy.

[0056] At 406, the routine includes determining whether the conditions for the AGS diagnostic have been met. The AGS diagnostic conditions may include, for example, determining whether a threshold duration has passed since the previous AGS diagnostic was performed. It should be understood that it may be appropriate to routinely perform the AGS diagnostic after a threshold duration has passed (e.g., after 7-10 days or, for example, after the engine has been running for 12 hours) or after a threshold number of engine start / stop conditions have passed (e.g., after 10 engine starts). It should be understood that, by default, it may be appropriate to initiate the diagnostic based on the routine as described above. However, in some examples, the AGS diagnostic routine may also be initiated in response to engine parameters outside the threshold. For example, if an engine parameter such as the engine coolant temperature exceeds a temperature threshold indicating an engine overheat during urban driving conditions, the AGS diagnostic routine may also be initiated to determine whether the AGS may be stuck closed, thereby contributing to increasing the engine coolant temperature. In this way, the AGS diagnostic routine may be routinely scheduled as a preventive diagnostic and / or performed as a countermeasure to diagnose or maintain the AGS system in response to an indication that the engine parameter is outside the threshold.

[0057] Additional or alternative conditions for initiating the AGS diagnostic may include an indication of daylight conditions. In one example, the daylight conditions may be determined by the output of a light sensor. In some examples, the light sensor may be an automatic dimming light sensor coupled to a rearview mirror, or a light sensor associated with automatic control of the vehicle's headlights, which may be located on the dashboard or on the hood of the vehicle (e.g., Figure 2 The exterior (e.g., Figure 2 In other examples, daylight conditions may be determined by a real-time weather report received at a controller of the vehicle or a real-time onboard clock indicating the time of day. As previously described, from an onboard communication and entertainment system (e.g., Figure 1 The data obtained by the vehicle communication and entertainment system 26 may include real-time and forecast weather conditions. Weather conditions such as cloud cover and precipitation (e.g., rain, snow, hail, etc.) can be obtained through various wireless communication device applications and weather forecast websites.

[0058] It should be appreciated that AGS diagnostics may be performed during non-daylight hours provided there is some indication of ambient light in front of the vehicle. This may include detecting ambient light from vehicle headlights (e.g., Figure 1headlights of vehicle 102 or another vehicle), ambient light in a parking facility, or light projected or reflected by any other suitable light source in front of the vehicle. In addition, it will be understood that, in one example, AGS diagnostics can be performed during any driving or non-driving mode and during any ambient temperature conditions. For example, AGS diagnostics can be performed during any driving mode, which may include, but are not limited to, idle conditions, engine off conditions, start / stop driving modes, city driving modes, highway driving modes, and electric vehicle modes. Because AGS diagnostics can be performed during any driving mode or non-driving mode and during ambient temperature conditions, robust diagnostics that are independent of the vehicle operator's driving habits and weather conditions are provided. Additional conditions for initiating AGS diagnostics may include a vehicle speed above a threshold speed, wherein the diagnostics are performed while the vehicle is being propelled.

[0059] If the conditions for the AGS diagnostic are not met, the routine proceeds to 408 where the routine includes continuing to adjust the AGS in response to engine operating conditions as described above (with reference to 404 ) before terminating.

[0060] If the conditions for AGS diagnostics are met, the routine proceeds to 410, where the routine includes initiating AGS diagnostics. Initiating AGS diagnostics may include detecting the presence of an AGS sensor located externally under the hood of the vehicle (such as a Figure 2 After initiating the AGS diagnostic, at 412 , the routine includes determining whether the active grille shutters are open (eg, fully open). As previously described with reference to Figure 3 As shown in the example position 306, the fully open position may allow a maximum amount of ambient airflow and / or ambient light to enter the engine compartment area and engine bay of the vehicle through the grille. The fully open position may be considered to be a maximum opening or a maximum percentage opening. In one example, determining whether the grille shutters are fully open may include: if the AGS system includes a position sensor, the controller receives a value from the position sensor (e.g., Figure 1 and Figure 2 AGS position sensor 115 of the embodiment receives sensor data. A light sensor (e.g., Figure 1-Figure 3 The AGS light sensor 113 may also provide an indication that the grille shutters are in a fully open position. The fully open grille shutter position may be correlated to a light sensor indication from behind the grille shutters that is equivalent to an ambient light sensor indication, which may be determined by a light sensor located in full exposure to ambient light (e.g., Figure 2 It will be appreciated that the light sensor being located behind the active grille shutter may include the light sensor being located at a portion of the grille shutter that is away from the front grille of the vehicle (e.g. Figure 1In other words, the light sensor being located behind the AGS may include the light sensor being located between the active grille shutters under the hood of the vehicle and the engine. Other methods of determining that the AGS is fully open may include the end stops (e.g., Figure 3 In yet another example, determining that the AGS is fully open may include determining whether the last commanded position of the AGS is a fully open position.

[0061] If the AGS is not fully open, the routine proceeds to 414 where the routine includes fully opening the active grille shutters. Fully opening the active grille shutters may include the controller sending a signal to the AGS motor to start the motor so as to actuate the mechanical linkage and adjust the AGS to the fully open position. In one example, this may include increasing the amount of opening to a maximum percentage opening. In some examples, this may include increasing the opening of the grille shutters until they contact an end stop (e.g., Figure 3 end stops 320). In an alternative embodiment, the AGS diagnostics may be performed by adjusting the AGS between a partially open and closed position. Thus, in this embodiment, the method at 414 may include increasing the amount of opening of the AGS so that they are partially open (e.g., 80% open), but they may not be fully open.

[0062] If the AGS is fully open at 412, or has been adjusted to the fully open position at 414, the routine continues to 416, where the routine includes monitoring a light sensor output of a light sensor located behind the AGS. Monitoring the light sensor response may include monitoring a first sensor response from a first light sensor located behind the AGS. In this manner, the amount of light entering through the AGS may be inferred, and changes to the position of the AGS (e.g., percent opening) may induce predictable and corresponding changes to the amount of light entering through the AGS. For example, if the AGS is fully open, a maximum amount of ambient light (e.g., Figure 1 and Figure 2of ambient light 116) can enter through the grille shutters and produce an increased sensor output (e.g., an increased voltage reading). Conversely, if the AGS is fully closed, a minimal amount of ambient light can enter through the openings between the grille shutters, thereby producing a reduced light sensor output. In other examples, monitoring the light sensor response may also include monitoring a first response from a second light sensor located externally under the hood of the vehicle. In this manner, a baseline ambient light level may be monitored to provide a baseline ambient light condition for comparison with the light response indicated by the first light sensor. In this manner, even if ambient light conditions change during AGS diagnostics, the light response from the first light sensor can be compared to current ambient light conditions. In particular, when the AGS is fully open, it may be appropriate that the first response of the first light sensor is closely correlated with the first response of the second light sensor because the AGS does not block ambient light from reaching the first sensor.

[0063] At 418 , the routine includes adjusting the grille shutters to a closed position and monitoring the light sensor response (e.g., output). In one example, adjusting the grille shutters to a closed position may include the vehicle controller sending a signal to the AGS motor to actuate a mechanical linkage coupled to the AGS and reduce the percentage opening of the grille shutters to 0%. In one example, this may include the grille shutters contacting an end stop (e.g., Figure 3 end stop 321), such as Figure 3 , as shown in example position 302 of . In this fully closed position, ambient light may be reduced or substantially prevented from entering the engine compartment through the grille, and thus the response (e.g., output) from a first light sensor located behind the AGS may be reduced. In an alternative embodiment, the method at 418 may include reducing the amount of opening of the AGS so that they are more closed but not fully closed (e.g., 10% open) compared to the position at 414. In addition to adjusting the grille shutters to the closed position at 418, the light sensor response is also monitored. Monitoring the light response may include monitoring the light response from the first light sensor and monitoring the light response from the second light sensor.

[0064] The routine then proceeds to 420, where the routine includes determining whether the light sensor response (e.g., output) of a light sensor (e.g., first light sensor 113) located behind the AGS at the open and closed positions is within a desired threshold. In one example, when the AGS is commanded to the open position, the desired threshold may include a threshold between a first light sensor output of a first light sensor located behind the grille shutters under the hood and a second light sensor output of a second light sensor located outside and exposed to ambient light under the hood. In one example, when the AGS is adjusted to the fully open position, the light indication (e.g., sensor output or sensor response) from the first sensor may be within a threshold of the light indication (e.g., sensor output or sensor response) from the second sensor. This is in part because the grille shutters do not obstruct ambient light from entering the grille and striking the first light sensor. In this way, when the grille shutters are fully open, the light indications from the first light sensor and the second light sensor are expected to be approximately the same. In addition, the desired threshold may include a threshold difference between a first sensor response from the first light sensor when the AGS is commanded to the open position and a second sensor response from the second light sensor when the AGS is commanded to the closed position. Specifically, when the AGS is in the fully open position, the light indication from the first sensor is expected to be greater than the light indication from the first sensor when the AGS is in the fully closed position. This is a result of the grille shutters blocking an increased amount of ambient light from reaching the first light sensor when the (one or more) grille shutter openings are reduced. Therefore, the first light sensor response can be expected to be greater than the threshold amount of the second light sensor response. Other thresholds may include comparing sensor data from one or more first light sensors if the AGS system includes more than one first light sensor. In some embodiments, a light sensor may be located behind each set of active grille shutters. In this way, it can be determined whether each set of grille shutters is adjusted as commanded. Further, if more than one light sensor is located behind the AGS, the average output of all light sensor data may be used to reduce variation and / or noise in the sensor data. In addition, in an embodiment of an AGS diagnostic that includes commanding the AGS between a partially open position and a partially closed position, the expected threshold may be different from the expected threshold when the AGS is commanded between a fully open position and a fully closed position. It should be understood that if a sudden or unexpected change in ambient light occurs during the diagnostic, the routine may be disabled.

[0065] If the light sensor response of the first light sensor is not within the expected threshold, the routine proceeds to 422, where the routine includes indicating degradation of the AGS system and determining a degraded AGS position based on the light sensor response(s). In one example, in response to a command to increase the opening of the AGS, the light indication from the first light sensor is expected to increase toward an ambient light level, which may be indicated by a second light sensor located externally under the hood. Additionally, in response to a command to move the AGS from an open position to a closed position, the light indication from the first light sensor is expected to decrease by more than a threshold light level. In this manner, the AGS may be diagnosed as being in a stuck position based on the first light sensor response not decreasing by more than a threshold amount when the AGS is commanded to close and / or the first light sensor response differing from the second light sensor response by more than a threshold when the AGS is commanded to open.

[0066] In another example, the AGS can be diagnosed as being in a stuck open position based on the first light sensor response not increasing by more than a threshold amount when the AGS is commanded to open, and / or the AGS can be diagnosed as being in a stuck open position when the first light sensor response differs from the second light sensor response by less than a threshold amount when the AGS is commanded to open.

[0067] Further, for embodiments of an engine system that includes an AGS position sensor, the AGS diagnostic may also confirm information regarding functionality of the position sensors and the AGS light sensor by monitoring the sensor outputs during the diagnostic. For example, if the output of the first AGS light sensor does decrease responsiveness to a command to close the grille shutters from an open position, and the AGS position sensor does not indicate a reduced opening of the grille shutter position, then this may indicate a degraded AGS position sensor. Alternatively, if the output of the first AGS light sensor does decrease responsiveness to a command to close the grille shutters, but the AGS position sensor indicates that the opening of the grille shutters does move to a closed position, then degradation of the AGS light sensor may be inferred. Other system sensor functions may be evaluated as part of the AGS diagnostic, including a temperature sensor proximate to the grille shutters.

[0068] The routine then continues to 424, where the routine includes setting a diagnostic code in response to an indication of AGS degradation and disabling AGS actuation. Setting the diagnostic code may include setting a code in the controller indicating that the AGS system is degraded, stuck in a position (e.g., open, closed, or somewhere between fully open and fully closed) or mispositioned. In addition to setting the diagnostic code, the controller may also illuminate a malfunction indicator light (MIL) on an operator display panel (not shown) in the passenger compartment of the vehicle. In one example, at 422, the AGS diagnostic may have determined that the AGS is stuck, and therefore a diagnostic code indicating this situation may be set. In another example, at 422, the AGS diagnostic may have determined that the AGS position sensor is degraded, and therefore a diagnostic code indicating this situation may be set. In this way, a specific degradation mode may be indicated. Optionally, at 424, the routine may further include moving the AGS to a default position if the AGS is not stuck. In one example, the default position may be a fully open position, or may be a maximum open position, but other default positions may also be suitable. Further, in response to an indication of a degraded AGS system, AGS actuation may be disabled so as to reduce the likelihood of damage to the AGS motor or mechanical linkage. Disabling AGS actuation may be in response to an indication of a stuck AGS. Specifically, disabling AGS actuation may include the controller not sending a signal to adjust the position of the AGS even when vehicle and / or engine operating conditions may indicate that adjustment of the grille shutters would otherwise be indicated. For example, in response to an indication that the grille shutters are stuck partially open, the grille shutters may not be commanded to the fully closed position even if the vehicle speed and engine coolant temperature are above their respective thresholds for adjusting the AGS to the fully closed position.

[0069] In other examples, rather than disabling future operation of the AGS system, it may be appropriate to continue operating the AGS at its current capacity without completely disabling the AGS system and any fuel consumption reduction benefits previously described that may be retained by continuing AGS operation (albeit at a limited capacity.) This may occur in examples where the AGS is unable to move to either the fully open or fully closed position due to obstructing debris, but the grille shutters may otherwise continue to be reliably controlled.

[0070] At 426, the routine includes adjusting engine parameters based on the degraded AGS position determined at 422. In some examples, this may include adjusting one or more of the engine fan, water pump, HVAC system, engine load, and vehicle auxiliary loads. As previously described, if the AGS is stuck in the closed position, this may reduce the amount of fresh intake air entering the vehicle grille to facilitate adequate engine cooling under certain engine operating conditions. Among other things, a stuck grille shutter may cause an unexpected increase in engine coolant temperature, so controlling (e.g., adjusting) appropriate engine parameters may mitigate potentially problematic temperature increases of engine components. In one example, in response to reaching a vehicle and / or engine operating condition that would cause a command to open the grille shutters, the controller may enable the cooling fan (e.g., Figure 1 The controller may also increase the cooling effect of the engine by increasing the electric fan 92 to compensate for the degraded AGS system. In another example, the controller may reduce the cooling output of the HVAC system to reduce the engine load and reduce the cooling demand of the engine system. After 426, the routine ends.

[0071] If the light sensor response is within the expected threshold at 420 , the routine proceeds to 428 where the controller may indicate that the AGS is not degraded and continue to adjust the AGS based on engine operating conditions as previously described. After 428 , the routine ends.

[0072] Now go to Figure 5 , which shows an engine system (such as Figure 1 The engine system 100) includes a predicted operation diagram 500 of the engine system 100, including controlling the AGS response to the engine operating conditions. The engine system can also have a light sensor located behind the active grille shutter and Figure 2 The second optical sensor 213 shown in FIG. 1 performs an AGS diagnostic routine (such as Figure 4 The AGS position may be controlled by a vehicle controller, and in response to an indication of degraded AGS position, the controller may adjust engine parameters to mitigate the effects of the degradation in order to maintain adequate engine cooling. By using an optical sensor to monitor for degradation or mispositioning of the AGS, a robust diagnostic is provided that may be performed during any driving or non-driving condition and during any ambient temperature. Figure 5Graph 500 depicts engine coolant temperature (ECT) at curve 502, engine speed (Ne) at curve 504, vehicle speed (VS) at curve 506, AGS opening position at curve 508, and ambient light indication at curve 510. It should be understood that, as previously described, the ambient light indication of curve 510 may be output from a light sensor that is not located in the engine compartment or behind the AGS. Instead, the ambient light level may be inferred from a sensor located outside the engine compartment. Examples of locations of ambient light sensors may include a vehicle dashboard, a rearview mirror, and near headlights. According to the present disclosure, graph 500 additionally includes a light indication from an AGS light sensor at curve 512, which is from a sensor located behind the AGS. It is understood that the sensor located behind the AGS may be located between the active grille shutter and the engine, under the vehicle hood, and on the side of the grille shutter away from the front of the vehicle. Graph 500 further includes a degradation indicator at curve 514 and a cooling fan operating mode at curve 516. All curves are depicted over time along the x-axis. Additionally, as shown, the magnitude of the parameter represented in any given curve increases from bottom to top along the y-axis.Time markers t1-t5 depict moments when significant events occur.

[0073] Prior to time t1, the engine speed (curve 504), vehicle speed (curve 506), and engine coolant temperature (curve 502) gradually increase, which may occur when the operator has an increased torque demand. Dashed line 503 represents an engine coolant temperature threshold for opening the AGS, above which the percentage opening of the active grille shutters may be commanded to increase and / or fully open to promote increased engine cooling by allowing an increased amount of fresh air to enter through the grille of the vehicle. As the vehicle propels forward, fresh air intake may be further increased. Dashed line 507 represents a vehicle speed threshold for closing the AGS, above which the opening of the active grille shutters may be commanded to decrease and / or fully close to reduce the entry of fresh air through the grille and reduce drag, thereby increasing fuel economy. Prior to time t1, the grille shutters remain closed because the ECT has not yet met the opening threshold temperature 503. The ambient light indication (plot 510) before time t1 starts out low and gradually increases, which may indicate driving in the morning hours when the sun is rising (e.g., ambient light levels increase toward daylight hours). Before time t1, the light indication from the AGS light sensor remains low (e.g., minimum) because the AGS is turned off, thereby preventing low levels of ambient light from entering through the grille shutter opening and reaching the light sensor. No degradation flag is indicated, and the cooling fan remains off before time t5.

[0074] At time t1, in response to the engine coolant temperature reaching threshold 503, the controller may send a signal to an actuator of the AGS to energize the AGS motor and actuate a mechanical linkage to increase the opening of one or more sets of active grille shutters (curve 508). Between t1 and t2, in response to increasing the opening of the active grille shutters, the light indication at the AGS sensor increases (curve 512) due to the increased airflow and the engine coolant temperature does not continue to increase (curve 502). The vehicle speed continues to increase through time t2, when the vehicle speed reaches and exceeds threshold 507. In response to the vehicle speed exceeding threshold 507, the controller may send a signal to an actuator of the active grille shutters to energize the AGS motor and actuate a mechanical linkage to reduce the opening of the active grille shutters (curve 508). In one example shown, at time t2, the active grille shutters are moved to a fully closed position and the light indication from the AGS sensor decreases accordingly (curve 512). The engine speed and vehicle speed continue to increase slightly before leveling off between times t2 and t3. The engine coolant temperature remains generally steady between times t2 and t5.

[0075] At t2, the ambient light conditions (curve 510) have reached an ambient light threshold 511 above which the AGS diagnostic may be initiated. It should be appreciated that the ambient light threshold may be any suitable value of ambient light and include one or more of daylight, moonlight, cloudy conditions, artificial light from a parking lot during nighttime hours, and reflection of vehicle headlights from a wall in front of the vehicle. For purposes of illustration, at some time between t2 and t3, the AGS is stuck in the off position.

[0076] The AGS diagnostic is initiated at time t3, and in response to initiating the diagnostic, the AGS is commanded to a fully open position (dashed curve 509), but the grille shutters are unable to provide a fully open position and remain closed (curve 508). As a result, the light indication from the AGS light sensor does not increase as expected. Specifically, with the AGS fully open, the AGS light sensor indication (curve 513) will be within the threshold of the ambient light indication (curve 510). Instead, the light indication from the AGS light sensor remains consistent with the AGS being closed (curve 512). At time t4, the AGS diagnostic includes commanding the AGS to a fully closed position. Because in the depicted example, the AGS is stuck, there is no change in the AGS position (curve 508) or the light indication at the AGS light sensor (curve 512). The ambient light indication remains relatively constant for the duration of the AGS diagnostic.

[0077] At time t5, the AGS diagnostic ends, and an indication of AGS degradation is marked at time t5 (curve 514) in response to the difference between the expected light indication from the AGS sensor and the ambient light indication between t3 and t4. In addition or optionally, if the output from the first light sensor (e.g., the light indication from the AGS sensor) does not change by more than a threshold when the AGS is commanded from an open position to a closed position, AGS degradation may also be indicated and marked. As previously described, indicating AGS degradation may include setting a diagnostic code and / or illuminating a malfunction indicator light (MIL) on an operator display in the vehicle passenger compartment. After time t5, the engine speed (curve 504) and the vehicle speed (curve 506) may gradually decrease, which may occur when the vehicle driver reduces the activation of the accelerator pedal, thereby reducing the torque demand. When the vehicle speed (curve 506) drops below the vehicle speed threshold 507 and / or when the engine coolant temperature increases by more than the ECT threshold 503, the controller may send a signal to the actuator of the AGS to increase the opening of the AGS. As a result of causing the degradation indication at time t5 due to the AGS being stuck, the AGS may not open as desired. As a result, the cooling fan may be activated (eg, enabled) to increase the flow of air through the radiator, heater core, and / or CAC (eg, Figure 1radiator 80, heater core 90 and / or CAC 18), thereby increasing the cooling effect on the engine. It should be understood that other engine parameters can be controlled in response to the indication of degradation, including increasing the engine cooling capacity by enabling one or more of the engine fan and water pump, and reducing one or more of the engine loads by reducing the HVAC system load and the vehicle auxiliary load. In this way, by using the optical sensor behind the AGS to diagnose the position of the active grille shutters, the degradation mode of the AGS can be identified and distinguished. These degradation modes may include, but are not limited to, mechanical degradation of the AGS system, which may include degradation of the AGS motor, stuck or damaged grille shutters, or degradation of the mechanical linkage between the AGS motor and the grille shutters. If the AGS system is so equipped, additional degradation modes that can be identified include a degraded AGS position sensor. The technical effect of using an optical sensor to indicate degradation of the AGS system is that partial AGS degradation can be inferred, where the AGS can still be adjusted to a limited capacity. As a result, the operation of the AGS can continue despite the limited capacity, thereby retaining the advantages of reduced fuel consumption to the greatest extent. Additionally, inferring the AGS position via the optical sensor by monitoring ambient temperature and engine temperature changes relative to the inferred AGS position is more reliable because the engine temperature may not respond immediately to AGS position changes and the engine temperature may change for a variety of reasons. Therefore, using the output of an optical sensor located behind the AGS within the engine compartment area of ​​the vehicle to diagnose the position of the AGS can allow for more accurate diagnosis of the AGS and additional sensors of the AGS system, including position or temperature.

[0078] A method includes: in response to the output of a first light sensor located under a hood of a vehicle, behind an active grille shutter (AGS), diagnosing the position of the AGS; and in response to the diagnosed position, adjusting an engine operating parameter. In a first example of the method, the method further includes: initiating the diagnosis in response to one or more of a threshold duration of time elapsed since a previous diagnosis, a vehicle speed above a threshold speed, and an ambient light condition outside the vehicle above a threshold level. A second example of the method optionally includes the first example and further includes indicating an ambient light condition above the threshold level via one or more of an output of a second light sensor located outside under a hood of the vehicle, a real-time weather report received at a controller of the vehicle, and a real-time onboard clock indicating the time of day.

[0079] A third example of a method optionally includes one or more of the first and second examples, and further includes wherein diagnosing the position of the AGS includes determining that the AGS is stuck in a closed position in response to an output of the first light sensor being below a threshold level after the AGS is commanded to an open position. A fourth example of a method optionally includes one or more of the first to third examples, and further includes wherein diagnosing the position of the AGS includes determining that the AGS is stuck in an open position in response to an output of the first light sensor being above a threshold level after the AGS is commanded to a closed position. A fifth example of a method optionally includes one or more of the first to fourth examples, and further includes wherein adjusting the engine parameters includes adjusting one or more of an engine fan, a water pump, an HVAC system, an engine load, and a vehicle auxiliary load.

[0080] Another method includes, in response to an indication that ambient light outside the vehicle exceeds a threshold level, adjusting an active grille shutter (AGS) of the vehicle to each of an open position and a closed position, and in response to a light condition behind the AGS being outside a threshold range, indicating degradation of the AGS. Adjusting the active grille shutter (AGS) of the vehicle to each of an open position and a closed position can be performed sequentially, including adjusting the AGS to open and then close under a first condition. Alternatively, the sequential adjustment can include adjusting the AGS to close and then open under a second condition different from the first condition. In a first example of the method, the method further includes adjusting an engine operating parameter in response to indicating degradation. A second example of the method optionally includes the first example and further includes, wherein adjusting the engine operating parameter includes adjusting one or more of an engine fan, a water pump, an HVAC system, an engine load, and a vehicle auxiliary load. A third example of the method optionally includes one or more of the first and second examples and further includes, wherein the light condition behind the AGS is measured via a light sensor positioned behind the AGS, within an engine compartment area of ​​the vehicle. A fourth example of the method optionally includes one or more of the first to third examples and further includes, in response to a light condition behind the AGS being outside a threshold range, indicating that the AGS is in a position different from the commanded position, and in response to a position sensor of the AGS indicating that the AGS is in the commanded position, indicating degradation of the position sensor. A fifth example of the method optionally includes one or more of the first to fourth examples and further includes, wherein the light condition includes a first measured light condition output by the light sensor when the AGS is commanded to an open position and a second measured light condition output by the light sensor when the AGS is commanded to a closed position, and wherein the light condition outside the threshold range includes the first measured light condition deviating from the second measured light condition by less than a threshold. A sixth example of the method optionally includes one or more of the first to fifth examples and further includes, wherein the light condition behind the AGS includes a light condition occurring when the AGS is commanded to an open position, and wherein the light condition outside the threshold range includes the light condition being at a level that differs by a threshold amount from a level indicated by ambient light. A seventh example of a method optionally includes one or more of the first to sixth examples and further includes moving the AGS to a default position in response to indicating degradation and disabling further adjustment of the AGS in response to engine operating conditions.

[0081] A system for a vehicle, comprising: an active grille shutter (AGS) located at a front end of the vehicle; a first light sensor located within the vehicle, behind and proximate to the AGS; and a controller including non-transitory instructions stored in a memory, the instructions for: monitoring an output of the first light sensor when the AGS is commanded to an open position and then to a closed position; diagnosing a position of the AGS in response to the output monitored by the first light sensor relative to a threshold; and adjusting an engine operating parameter in response to the diagnosed position. In a first example of the method, the method further includes a second light sensor located proximate to one or more of a rearview mirror, a vehicle instrument panel, and a vehicle headlight, and wherein the threshold comprises one or more of: a first threshold difference between the output of the first light sensor when the AGS is in the open position and the output of the first light sensor when the AGS is in the closed position, and a second threshold difference between the output of the first light sensor and the output of the second light sensor when the AGS is commanded to the open position. A second example of the method optionally includes the first example, and further includes where the instructions further include instructions for determining that the AGS is in a stuck position in response to an output of the first sensor being below a threshold level after the AGS is commanded to the open position. A third example of the method optionally includes one or more of the first example and the second example, and further includes where the instructions further include instructions for determining that the AGS is in a stuck position in response to an output of the first light sensor being above a threshold level after the AGS is commanded to the closed position. A fourth example of the method optionally includes one or more of the first to third examples, and further includes where adjusting the engine operating parameters includes one or more of the following: increasing engine cooling capacity by enabling one or more of an engine fan and a water pump, and reducing engine load by reducing one or more of an HVAC system load and a vehicle auxiliary load. A fifth example of the method optionally includes one or more of the first to fourth examples, and further includes a position sensor for indicating the position of the AGS, and wherein the instructions further include instructions for indicating that the AGS is in the command position based on the monitored output of the light sensor and the output of the position sensor, and indicating degradation of the position sensor in response to determining that the AGS is in a position different from the command position.

[0082] In another representation, a method includes, in response to a request to initiate a diagnostic of an active grille shutter (AGS) located at a front end of a vehicle, adjusting the AGS between an open position and a closed position, and during a first condition, indicating degradation of the AGS in response to an output of a light sensor located behind the AGS not changing by a threshold amount when adjusting the AGS between the open position and the closed position; and during a second condition, indicating that the AGS is not degraded and continuing to adjust the AGS based on engine operating conditions in response to the output changing by at least a threshold amount when adjusting the AGS between the open position and the closed position.

[0083] Note 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 a non-temporary memory and can be executed by a control system including a controller in combination with various sensors, actuators, and other engine hardware. 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-threaded, etc. In this way, the various actions, operations, and / or functions shown can be executed in the order shown, executed in parallel, or can be omitted in some cases. Similarly, the processing order is not required to achieve the features and advantages of the example embodiments described herein, but is provided for ease of illustration and description. Depending on the specific strategy used, one or more of the actions, operations, and / or functions shown can be repeatedly performed. Further, the described actions, operations, and / or functions can graphically represent the code in the non-temporary memory of a computer-readable storage medium to be programmed into the engine control system, wherein the described actions are implemented by executing the instructions in a system including various engine hardware components in combination with an electronic controller.

[0084] It should be understood that the configurations and routines disclosed herein are exemplary in nature, and these specific embodiments are not to be considered in a limiting sense, as many variations are possible. For example, the above-described techniques may be applied to V-6, I-4, I-6, V-12, opposed 4, 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.

[0085] The appended claims particularly point out certain combinations and subcombinations regarded as novel and non-obvious. These claims may refer to "an" element or a "first" element or the equivalent thereof. These claims should be understood to include the incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amendment of the present claims or by presentation of new claims in this or a related application. Such claims, whether broader, narrower, the same, or different in scope to the original claims, are likewise deemed to be included within the subject matter of the present disclosure.

Claims

1. A method for an engine, the method comprising: When the vehicle is propelled by the engine, diagnosing a position of an active grille shutter (AGS) responsive to output of a first light sensor located under a hood of the vehicle and behind an active grille shutter (AGS) relative to ambient light sensed by a second light sensor; and An engine operating parameter is adjusted in response to the diagnosed position relative to the commanded position of the AGS. 2 . The method of claim 1 , wherein the diagnosis is initiated in response to one or more of a threshold duration of time elapsed since a previous diagnosis, a vehicle speed above a threshold speed, and an ambient light condition of ambient light outside the vehicle above a threshold level.

3. The method of claim 2, wherein the ambient light condition being above the threshold level is indicated by one or more of an output of the second light sensor located externally under the hood of the vehicle, a real-time weather report received at a controller of the vehicle, and a real-time onboard clock indicating the time of day. 4 . The method of claim 1 , wherein diagnosing the position of the AGS comprises determining that the AGS is stuck in a closed position in response to the output of the first light sensor being below a threshold level after the AGS is commanded to an open position. 5 . The method of claim 1 , wherein diagnosing the position of the AGS comprises determining that the AGS is stuck in an open position in response to the output of the first light sensor being above a threshold level after the AGS is commanded to a closed position. 6 . The method of claim 1 , wherein adjusting the engine operating parameters comprises one or more of adjusting one or more of an engine fan, a water pump, an HVAC system, an engine load, and a vehicle auxiliary load. 7 . The method of claim 1 , wherein diagnosing the position of the AGS comprises determining that the AGS is in a position different than a commanded position in response to the output of the first light sensor being outside of a threshold range. 8 . The method of claim 7 , further comprising indicating degradation of the position sensor in response to a position sensor of the AGS indicating that the AGS is in the commanded position.

9. The method of claim 7, wherein the output of the first light sensor comprises a first measured light condition output by the light sensor when the AGS is commanded to an open position and a second measured light condition output by the light sensor when the AGS is commanded to a closed position, and wherein the output of the first light sensor outside the threshold range comprises the first measured light condition deviating from the second measured light condition by less than a threshold.

10. A system for a vehicle, the system comprising: Active grille shutters, or AGS, located at the front end of the vehicle; a first light sensor located within the vehicle and behind and proximate to the AGS; as well as A controller comprising non-transitory instructions stored in a memory, the instructions being for: monitoring an output of the first light sensor while commanding the AGS into an open position and then into a closed position; diagnosing a position of the AGS in response to a monitored output of the first light sensor relative to ambient light sensed by a second light sensor; and An engine operating parameter is adjusted in response to the diagnosed position relative to the commanded position of the AGS.

11. The system of claim 10, further comprising the second light sensor located proximate one or more of a rearview mirror, a vehicle dashboard, and a vehicle headlight.

12. The system of claim 10, wherein the instructions further comprise instructions for determining that the AGS is stuck in a closed position in response to an output of the first light sensor being below a threshold level after the AGS is commanded to the open position.

13. The system of claim 10, wherein the instructions further comprise instructions for determining that the AGS is in a stuck open position in response to an output of the first light sensor being above a threshold level after the AGS is commanded to the closed position.

14. The system of claim 10, wherein adjusting the engine operating parameters comprises one or more of: increasing engine cooling capacity by activating one or more of an engine fan and a water pump, and reducing engine load by reducing one or more of an HVAC system load and a vehicle auxiliary load.

15. The system of claim 10, further comprising a position sensor for indicating a position of the AGS, and wherein the instructions further comprise instructions for indicating that the AGS is at the command position based on a monitored output of the light sensor and an output of the position sensor, and indicating degradation of the position sensor in response to determining that the AGS is at a position different from the command position.

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