METHOD AND SYSTEM FOR DIAGNOSTICING A PARTICLE FILTER SENSOR

Abstract

Vehicle operating procedures, comprehensive: as a response to a diagnostic request from an exhaust system sensor, rotating an engine in a reverse direction without supplying fuel to the engine; Receiving data from a differential pressure sensor to a controller while the engine is being rotated in reverse, and Adjusting the engine operation via the control unit in response to data from the differential pressure sensor.

Description

Area

[0001] The present invention relates to a method and a system for determining the presence or absence of impairment of a differential pressure sensor that detects a pressure change across a gasoline particulate filter. The methods and systems can be particularly useful for direct fuel injection engines that are occasionally operated in a stratified charge mode. Background and brief description

[0002] A spark-ignition gasoline or Otto engine can incorporate direct fuel injection. Fuel can be injected directly into an engine cylinder, allowing the vaporization of the injected fuel to cool the charge within the cylinder. By cooling the cylinder charge, the engine can operate at higher loads before knocking occurs compared to an engine with port fuel injection. Consequently, the engine can operate more efficiently and deliver more power than a port fuel injection engine. However, direct fuel injection into a cylinder can also cause stratification of the injected fuel within the cylinder, resulting in carbon-rich exhaust gas. This carbon-rich exhaust gas can be trapped in a particulate filter, where it can then be oxidized, thus reducing the amount of particulate matter released into the atmosphere.Over time, the particulate filter can become filled with carbonaceous soot, necessitating regeneration. One way to determine whether a certain amount of carbonaceous soot has accumulated in the particulate filter is to measure a pressure change or differential across it. If the particulate filter is clogged with carbonaceous soot, a higher differential pressure may be observed under high airflow. However, it is possible for a differential pressure sensor hose to become detached from its secured position due to maintenance or unforeseen circumstances. If the differential pressure sensor hose becomes detached, it can be difficult to determine whether the sensor is providing reliable information.Therefore, it may be desirable to provide a way to determine whether the differential pressure sensor data is reliable or not.

[0003] Documents US 2008 / 0202096A1 and US 2004 / 0226530A1 describe methods and systems for diagnosing a particulate filter sensor of an exhaust system.

[0004] According to US 2008 / 0202096A1, to start an engine, a crankshaft is first reversed by a target amount of rotation and then forwards. As the crankshaft reverses, residual gas from the exhaust port is drawn into the combustion chamber, and residual gas from the combustion chamber is discharged into the intake port. As the crankshaft rotates forwards, the residual gas, along with air from the intake port, is drawn into the combustion chamber and combusted. The target amount of reverse rotation is set so that in all cylinders, a reverse gas flow is created from the combustion chamber to the intake port, or in at least one cylinder, a reverse gas flow is created from the exhaust port, through the combustion chamber, to the intake port.

[0005] US Patent 2004 / 0226530A1 discloses a particulate regeneration system for an engine. The particulate regeneration system may include a particulate filter configured to remove particles from an engine exhaust stream and a diesel oxidation catalyst located upstream of the particulate filter to facilitate the oxidation of the captured particles. The particulate regeneration system may further include a regeneration device located upstream of the diesel oxidation catalyst and configured to selectively heat the exhaust gas above an oxidation temperature of the captured particles, as well as a selective catalytic reduction device located downstream of the particulate filter to remove NOx from the engine exhaust. The particulate regeneration system may also include a control unit that communicates with the regeneration device and the engine.The controller can be configured to change the engine operation in response to the initiation of a regeneration event.

[0006] Based on known methods in which the combustion engine is started to perform sensor diagnostics, the invention aims to provide a vehicle operating method and a system that enables sensor diagnostics in the exhaust system without the vehicle user noticing. This objective is achieved by the features of the independent claims. Further developments of the invention are described in the dependent claims.

[0007] Accordingly, a vehicle operating procedure comprises the following: in response to a diagnostic request from an exhaust system sensor, rotating an engine in a reverse direction without supplying fuel to the engine; receiving data from a differential pressure sensor to a control unit while the engine is being rotated in reverse; and adjusting engine operation via the control unit in response to the data from the differential pressure sensor.

[0008] By rotating the engine backwards when it is not burning air and fuel, it may be possible to achieve the technical result of a higher flow rate through the engine than if the engine were rotating forwards while not burning air and fuel, thus improving the signal-to-noise ratio of the exhaust gas sensor output. Furthermore, rotating the engine without combustion allows exhaust gas sensor diagnostics to be performed when no vehicle occupants are present, making the diagnostics less noticeable. Additionally, exhaust gas sensor diagnostics can be performed selectively during engine operation, at times when they are less likely to be detected.

[0009] The described approach offers several advantages. For example, it can enable improved sensor diagnostics. Furthermore, it can provide diagnostics while the engine is running or not, allowing for timely diagnosis of an exhaust gas sensor. Additionally, it can provide an improved signal-to-noise ratio for the exhaust gas sensor output.

[0010] The aforementioned advantages, as well as other advantages and features of the present description, are readily apparent from the following detailed description, whether considered on its own or in conjunction with the accompanying drawings.

[0011] It is understood that the foregoing summary is provided to introduce, in simplified form, a selection of concepts that are described in more detail in the detailed description. It is not intended to identify important or essential features of the claimed subject matter, the scope of which is defined solely by the claims following the detailed description. Furthermore, the claimed subject matter is not limited to implementations that overcome the disadvantages mentioned above or in any part of this disclosure. Brief description of the drawings

[0012] The advantages described here become more fully apparent from reading an example of an embodiment, referred to here as the detailed description, either on its own or with reference to the drawings, in which the following applies: Fig. Figure 1 is a schematic representation of an engine; Fig. Figure 2 is a schematic representation of a hybrid vehicle powertrain, which includes the engine from Fig. 1 includes; Fig. 3A and Fig. 3B shows an example of a motor valve control; Fig. 4 is a sequence that describes vehicle operation during exhaust gas sensor diagnostics according to the procedure from Fig. 5A-5C illustrated; and Fig. Figures 5A-5C show an exemplary procedure for diagnosing an exhaust system sensor. Detailed description

[0013] This description concerns the diagnostic operation of a differential pressure sensor that measures pressure on opposite sides of a particulate filter. The particulate filter can be integrated into a vehicle with a spark-ignition engine, as in Fig. 1 shown. The engine can be part of a hybrid vehicle, as in Fig. 2 shown. The engine may also feature an inlet and exhaust valve control system that provides a higher flow through the engine when the engine is rotated in a reverse direction, as shown in Fig. 3A and Fig. 3B illustrates this. The vehicle can be operated as shown. Fig. 4 shown according to the procedure from Fig. 5A-5C can be operated.

[0014] With reference to Fig. 1 is an internal combustion engine 10 comprising a plurality of cylinders, one of which is in Fig. As shown in Figure 1, the engine 10 is controlled by the electronic engine control unit 12. The engine 10 consists of a cylinder head 35 and a block 33, which enclose a combustion chamber 30 and cylinder walls 32. A piston 36 is positioned within the block and moves back and forth via a connection to a crankshaft 40. A flywheel 97 and a ring gear 99 are coupled to the crankshaft 40. A starter 96 (e.g., a low-voltage electric motor (operated at less than 30 volts)) includes a pinion shaft 98 and a pinion 95. The pinion shaft 98 can selectively drive the pinion 95 so that it engages the ring gear 99. The starter 96 can be mounted directly on the front or rear of the engine. The starter 96 can rotate the engine 10 in either a forward or reverse direction. In some examples, the starter 96 can selectively supply torque to the crankshaft 40 via a belt or chain.In one example, the starter 96 is in a resting state when it is not engaged with the engine crankshaft. According to the illustration, the combustion chamber 30 communicates with an intake manifold 44 and an exhaust manifold 48 via an intake valve 52 and an exhaust valve 54, respectively. Each intake and exhaust valve can be actuated by an intake cam 51 and an exhaust cam 53. The position of the intake cam 51 can be determined by an intake cam sensor 55. The position of the exhaust cam 53 can be determined by an exhaust cam sensor 57. The intake valve 52 can be selectively activated and deactivated by a valve activation device 59. The exhaust valve 54 can be selectively activated and deactivated by the valve activation device 58. The valve activation devices 58 and 59 can be hydraulic and / or electromechanical.

[0015] The fuel injection device 66 is positioned, as shown, to inject fuel directly into the cylinder 30, a process known to those skilled in the art as direct injection. The fuel injection device 66 delivers liquid fuel proportionally to the pulse width from the controller 12. The fuel is supplied to the fuel injection device 66 by a fuel system (not shown) comprising a fuel tank, a fuel pump, and a fuel distributor (not shown). In one example, a two-stage, high-pressure fuel system can be used to generate higher fuel pressures.

[0016] Furthermore, the intake manifold 44 is connected to the engine air intake 42, as shown in the illustration. An optional electronic throttle 62 sets the position of a throttle valve 64 to control the airflow from the air intake 42 to the intake manifold 44. In some examples, the throttle 62 and the throttle valve 64 can be positioned between the intake valve 52 and the intake manifold 44 such that the throttle 62 acts as an intake port throttle. An air filter 43 cleans the air entering the engine air intake 42.

[0017] The distributorless ignition system 88 provides a spark to the combustion chamber 30 via a spark plug 92 in response to the control unit 12. According to the illustration, a wideband lambda sensor (Universal Exhaust Gas Oxygen Sensor - UEGO sensor) 126 is coupled to the exhaust manifold 48 upstream of a catalyst 70. Alternatively, the UEGO sensor 126 can be replaced by a binary lambda sensor. The catalyst 70 can, in one example, contain multiple catalyst honeycomb elements. In another example, multiple emission control devices, each containing multiple honeycomb elements, can be used. The catalyst 70 can, in one example, be a three-way catalyst. Exhaust gas flows in one direction from the exhaust valve 54 to a silencer 72 when the engine 10 rotates forward, burning air and fuel. A particulate filter 71 is located downstream of the condenser 70 according to the direction of the exhaust gas flow.A differential pressure sensor 38 detects a pressure difference between the front 71A and rear 71B of the particulate filter 71. Specifically, an upstream inlet duct 38A detects pressure upstream of the particulate filter 71 via a hose 38C, and a downstream inlet duct 38B detects pressure downstream of the particulate filter 71 via a hose 38D, according to the direction of the exhaust gas flow. The silencer 72 is positioned downstream of the particulate filter 71 and includes an outlet valve 73 for selectively bypassing noise-limiting media 80. The outlet valve 73 allows exhaust gas to flow directly into the atmosphere via an outlet 74 when the outlet valve 73 is open. When the outlet valve 73 is closed, the exhaust gas passes through the noise-limiting media 80 and the outlet 75.

[0018] Control 12 is in Fig. Figure 1 shows a conventional microcomputer comprising: a microprocessor unit 102, input / output channels 104, a read-only memory 106 (e.g., non-volatile memory), a random access memory 108, a keep-alive memory 110, and a conventional data bus.According to the diagram, in addition to the signals discussed previously, the control unit 12 receives various signals from sensors connected to the motor 10, including: an engine coolant temperature (ECT) from temperature sensor 112, which is connected to a cooling sleeve 114; a position sensor 134, which is connected to an accelerator pedal 130 to detect the force exerted by a foot 132; a position sensor 154, which is connected to a brake pedal 150 to detect the force exerted by a foot 152; a manifold pressure (MAP) measurement from a pressure sensor 122, which is connected to the intake manifold 44; an engine position sensor from a Hall effect sensor 118, which detects the position of the crankshaft 40; and a measurement of the mass of air entering the engine from a sensor 120. and a measurement of the throttle position from a sensor 68.Atmospheric pressure can also be detected for processing by the controller 12 (sensor not shown). In a preferred aspect of the present description, the motor position sensor 118 generates a predetermined number of evenly spaced pulses with each revolution of the crankshaft, from which the motor speed (rpm) can be determined.

[0019] During operation, each cylinder in the engine 10 typically goes through a four-stroke cycle: The cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. During the intake stroke, the exhaust valve 54 generally closes and the intake valve 52 opens. Air is introduced into the combustion chamber 30 via the intake manifold 44, and the piston 36 moves toward the bottom of the cylinder to increase the volume within the combustion chamber 30. The position at which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 has reached its maximum volume) is typically referred to by those skilled in the art as bottom dead center (BDC).

[0020] During the compression stroke, the inlet valve 52 and the exhaust valve 54 are closed. The piston 36 moves towards the cylinder head to compress the air within the combustion chamber 30. The point at which the piston 36 is closest to the cylinder head at the end of its stroke (e.g., when the combustion chamber 30 has its smallest volume) is typically referred to by those skilled in the art as top dead center (TDC). In a process subsequently referred to as injection, fuel is introduced into the combustion chamber. In a process subsequently referred to as ignition, the injected fuel is ignited by known ignition means, such as the spark plug 92, resulting in combustion.

[0021] During the power stroke, the expanding gases push the piston 36 back to bottom dead center (BDC). The crankshaft 40 converts piston movements into torque of the crankshaft. Finally, during the exhaust stroke, the exhaust valve 54 opens to release the burnt air-fuel mixture to the exhaust manifold 48, and the piston returns to top dead center (TDC). It should be noted that the above is merely an example and that the timing of the opening and / or closing of the intake and exhaust valves can vary, for example, to provide positive or negative valve overlap, late closing of the intake valve, or various other examples.

[0022] Fig. Figure 2 is a block diagram of a vehicle 225, which includes a powertrain 200. The powertrain consists of Fig. 2 includes the one in Fig. Motor 10 shown in section 1. The drive train 200 can be driven by motor 10. Motor 10 can be equipped with an engine starting system that is in Fig. The engine can be started either as shown in Figure 1 or via a driveline integrated starter / generator (DISG) 240. The DISG 240 (e.g., a high-voltage electric machine (operated at more than 30 volts)) can also be referred to as an electric machine, an electric motor, and / or a generator. The DISG 240 can rotate the engine in a forward direction (e.g., clockwise when viewed from the front of the engine 10) or a reverse direction (e.g., counterclockwise when viewed from the rear of the engine 10). Furthermore, the torque of the engine 10 can be adjusted via a torque actuator 204, such as a fuel injection device, a throttle, etc.

[0023] An internal combustion engine output torque can be transmitted via a dual-mass flywheel 215 to the input side of a drivetrain release clutch 236 from the rear 294 of the engine 10. The release clutch 236 can be electrically or hydraulically actuated. In this example, the release clutch 236 can be operated by fluid supplied by a mechanically driven transmission fluid pump 295 or an electrically driven transmission fluid pump 299. The downstream side of the release clutch 236 is mechanically coupled to the input shaft 237 of the DISG, as shown in the illustration.

[0024] The DISG 240 can be operated to provide 200 torque to the powertrain or to convert powertrain torque into electrical energy to be stored in an electrical energy storage device 275. The DISG 240 has a higher output torque capacity than the one in Fig. 1. Starter 96 shown. Furthermore, the DISG 240 directly drives the drivetrain 200 or is directly driven by the drivetrain 200. There are no belts, gears, or chains to couple the DISG 240 to the drivetrain 200. Rather, the DISG 240 rotates at the same speed as the drivetrain 200. The electrical energy storage device 275 (e.g., high-voltage battery or power source) can be a battery, a capacitor, or an inductor. The downstream side of the DISG 240 is mechanically coupled to the impeller 285 of the torque converter 206 via the shaft 241. The upstream side of the DISG 240 is mechanically coupled to the release clutch 236.

[0025] The torque converter 206 includes a turbine 286 to output torque to an input shaft 270. The input shaft 270 mechanically couples the torque converter 206 to the automatic transmission 208. The torque converter 206 also includes a torque converter bypass lock-up clutch 212 (TCC). When the TCC is locked, the torque is transmitted directly from the impeller 285 to the turbine 286. The TCC is electrically operated by the control unit 12. Alternatively, the TCC can be hydraulically locked. In this example, the torque converter can be considered a component of the transmission.

[0026] When the torque converter lock-up clutch 212 is completely disengaged, the torque converter 206 transmits engine torque to the automatic transmission 208 via a fluid transfer between the torque converter turbine 286 and the torque request 285, thus enabling torque multiplication.

[0027] When the torque converter lock-up clutch 212 is fully engaged, the engine's output torque is transmitted directly to an input shaft (not shown) of the transmission 208 via the torque converter clutch. Alternatively, the torque converter lock-up clutch 212 can be partially engaged, allowing the amount of torque transmitted directly to the transmission to be adjusted. The control unit 12 can be configured to adjust the amount of torque transmitted by the torque converter 212 by adjusting the torque converter lock-up clutch in response to different engine operating conditions or based on a driver-specific engine operating request.

[0028] The automatic transmission 208 includes transmission clutches (e.g., gears 1-6) 211 and the forward clutch 210. The transmission clutches 211 (e.g., gears 1-10) and the forward clutch 210 can be selectively engaged to propel a vehicle. The torque output from the automatic transmission 208 can, in turn, be transmitted to the wheels 216 to propel the vehicle via an output shaft 260. Specifically, the automatic transmission 208 can transmit an input drive torque at the input shaft 270 in response to a driving condition of the vehicle before transmitting an output drive torque to the wheels 216.

[0029] Furthermore, a frictional force can be applied to the wheels 216 by engaging the wheel brakes 218. In one example, the wheel brakes 218 can be applied in response to the driver pressing a brake pedal with their foot (not shown). In other examples, the control unit 12 or a control unit connected to the control unit 12 can cause the wheel brakes to engage. Likewise, a frictional force on the wheels 216 can be reduced by releasing the wheel brakes 218 in response to the driver releasing their foot from a brake pedal. Additionally, the vehicle brakes can apply a frictional force to the wheels 216 via the control unit 12 as part of an automated engine stop procedure.

[0030] The controller 12 can be configured to receive inputs from the motor 10, as in Fig. Figure 1 shows in more detail how to receive and control a torque output from the engine and / or the operation of the torque converter, transmission, DISG, clutches, and / or brakes accordingly. For example, engine torque output can be controlled by adjusting a combination of ignition timing, fuel pulse width, fuel pulse rate, and / or air charge, while controlling throttle opening and / or valve timing, valve lift, and boost pressure for turbocharged or supercharged engines. In the case of a diesel engine, the controller 12 can control engine torque output by controlling a combination of fuel pulse width, fuel pulse rate, and air charge. In all cases, engine control can be performed on a cylinder-by-cylinder basis to control engine torque output.The controller 12 can also regulate the torque output and electrical energy generation of a DISG by adjusting the current flowing to the field and / or armature windings of the DISG, as is known in the art. The controller 12 receives the DISG position via a position sensor 271, which also indicates the position of the shaft 241 and the mechanically driven transmission fluid pump 295. The controller 12 can convert the transmission input shaft position into an input shaft speed by differentiating a signal from the position sensor 271. The controller 12 can receive the transmission output shaft torque from a torque sensor 272. Alternatively, the sensor 272 can be a position sensor or a combination of torque and position sensors. If the sensor 272 is a position sensor, the controller 12 differentiates a position signal to determine the transmission output shaft speed.The control unit 12 can also differentiate a transmission output shaft speed in order to determine the transmission output shaft acceleration.

[0031] If the conditions for an idle shutdown are met, the control unit 12 can initiate an engine shutdown by cutting off the fuel and / or ignition to the engine. However, in some cases, the engine may continue to rotate. To maintain a certain level of torsional vibration stress in the transmission, the control unit 12 can also ground rotating elements of the transmission 208 to a housing 259 of the transmission and thereby to the vehicle frame. If the conditions for restarting the engine are met and / or a vehicle operator wishes to start the vehicle, the control unit 12 can restart the engine 10 by cranking the engine 10 and resuming cylinder combustion.

[0032] The system made of Fig. 1 and Fig. 2 provides a system comprising: a vehicle incorporating an internal combustion engine; a motor selectively coupled to the internal combustion engine; and a controller containing executable instructions stored in non-volatile memory to rotate the internal combustion engine in reverse without burning air and fuel in response to an exhaust gas sensor diagnostic request, as well as instructions to propel the vehicle via the engine. The system further comprises additional instructions to burn air and fuel in the internal combustion engine and to rotate the internal combustion engine in a forward direction. The system further comprises a particulate filter and an exhaust valve located in an exhaust system coupled to the internal combustion engine, with the exhaust valve located downstream of the particulate filter.The system further includes additional instructions to open and close the exhaust valve while the internal combustion engine is rotated in reverse. The system further includes a differential pressure sensor configured to detect pressure on two opposite sides of the particulate filter. The system further includes additional instructions to compare the differential pressure sensor output with the exhaust valve open to the differential pressure sensor output with the exhaust valve closed. The system further includes additional instructions to adjust the operation of the internal combustion engine in response to this comparison. The system further includes the fact that the engine is an integrated starter / generator.

[0033] Now, with reference to Fig. Figure 3A shows exemplary valve timing for a first internal combustion engine. The forward and reverse directions of engine rotation are indicated by arrows. The exhaust valve opening time is represented by the outer ring 303. The intake valve opening time is represented by the inner ring 301. The valve timings are relative to the top dead center (TDC) and bottom dead center (BDC) of cylinder positions. The exhaust valve closing time (EVC) when the engine is rotated in a forward direction is at 302. The exhaust valve opening time (EVO) when the engine is rotated in a forward direction is at 306. The intake valve closing time (IVC) when the engine is rotated in a forward direction is at 308. The intake valve opening time (IVO) when the engine is rotated in a forward direction is at 304.When the motor is rotated in reverse, EVO occurs at 302 and EVC occurs at 306. IVO occurs at 308 and IVC occurs at 304.

[0034] This allows us to observe that the opening duration of the intake valve is longer than the opening duration of the exhaust valve. Furthermore, when rotating the engine forward, IVO is near top dead center (TDC) and IVC is near bottom dead center (BDC). When rotating the engine forward, EVO is after BDC and EVC is after TDC. Rotating the engine backward allows air to be drawn in from the exhaust manifold and expelled to the intake manifold, so that when the exhaust valve is open, air is drawn into the cylinder and when the intake valve is open, it is expelled from the cylinder. Therefore, the airflow through the engine when it is rotated forward with an open intake throttle and no fuel supply is greater than the airflow through the engine when it is rotated backward at the same engine speed with an open intake throttle and no fuel supply.The increased airflow through the engine while rotating forward at initial speed can be attributed to the longer opening duration of the intake valve and its opening and closing timing. The reduced airflow through the engine while rotating backward at initial speed can be attributed to the shorter opening duration of the exhaust valve and its opening and closing timing compared to the intake valve. However, rotating the engine backward with the valve timing controls... Fig. 3A may still be useful in diagnosing an exhaust gas sensor, as damage to the silencer can cause a pressure drop at the particulate filter when the engine is turned in reverse.

[0035] Now, with reference to Fig. Figure 3B shows exemplary valve timings for rotating an engine in a reverse direction (e.g., counterclockwise) with a higher flow rate when diagnosing an exhaust gas sensor. The forward and reverse directions of engine rotation are indicated by arrows. The exhaust valve opening time is represented by the outer ring 303. The intake valve opening time is represented by the inner ring 301. The valve timings are relative to the top dead center (TDC) and bottom dead center (BDC) of cylinder positions. The exhaust valve closing time (EVC) when the engine is rotated in a forward direction is 310. The exhaust valve opening time (EVO) when the engine is rotated in a forward direction is 314. The intake valve closing time (IVC) when the engine is rotated in a forward direction is 316.The intake valve opening time (IVO) when the engine is rotated forward is 312. When the engine is rotated reverse, EVO occurs at 310 and EVC at 314. IVO occurs at 316 and IVC at 312.

[0036] This allows us to observe that the opening duration of the exhaust valve is longer than the opening duration of the intake valve. Furthermore, when rotating the engine forward, IVO is close to top dead center (TDC) and IVC is well before bottom dead center (BDC). When rotating the engine forward, EVO is close to BDC and EVC is close to TDC. Rotating the engine backward allows air to be drawn in from the exhaust manifold and expelled to the intake manifold, so that when the exhaust valve is open, air is drawn into the cylinder and when the intake valve is open, it is expelled from the cylinder. For these reasons, the airflow through the engine when it is rotated backward with an open intake throttle and no fuel supply is greater than the airflow through the engine when it is rotated forward at the same engine speed with an open intake throttle and no fuel supply.The increased airflow through the engine while it is being rotated in reverse at initial speed can be attributed to the longer opening duration of the exhaust valve and its opening and closing timing. The reduced airflow through the engine while it is being rotated in forward direction at initial speed can be attributed to the shorter opening duration of the intake valve and its opening and closing timing compared to the opening duration and closing times of the exhaust valve.Therefore, whether the airflow through an engine while rotating forward at a first speed is greater than the airflow through the engine while rotating in reverse at that first speed can depend on intake and exhaust valve timing, which includes valve opening durations and valve opening and closing times. Consequently, for some engine designs, rotating an engine forward provides more airflow for a given engine speed compared to rotating the same engine in reverse at the same speed. Conversely, other engines may provide more airflow when rotated in reverse at a given engine speed compared to rotating the same engine forward at the same speed.Thus, the direction of engine rotation can be selected to increase airflow through the engine, allowing the engine to be run at a lower speed when diagnosing exhaust gas sensors. For example, if rotating a particular engine in reverse at a desired speed provides a greater airflow through the engine than rotating it forward at the same speed, then the engine can be run in reverse to improve the signal-to-noise ratio of the exhaust gas sensor when diagnosing exhaust gas sensors.

[0037] Now, with reference to Fig. 4 shows a vehicle operating sequence. The vehicle operating sequence from Fig. 4 can be accessed via the system from Fig. 1 and Fig. 2. The vehicle operating sequence can also be provided based on the procedure from Fig. 5A-5C will be provided.

[0038] The first course from the top Fig. Figure 4 shows the diagnostic request state of an exhaust gas sensor (e.g., the gasoline particulate filter sensor (BPF sensor)) over time. The vertical axis represents the exhaust gas sensor diagnostic state, with an exhaust gas sensor diagnostic request occurring when curve 402 is at a higher level near the arrow of the vertical axis. An exhaust gas sensor diagnostic request is not occurring when curve 402 is at a lower level near the horizontal axis. The horizontal axis represents time, with time increasing from the left side of the curve to the right side.

[0039] The second course from the top Fig. 4 is a path of an exhaust valve (e.g. 73 from Fig. 1) relative to time. The exhaust valve is open when curve 404 is at a higher level near the arrow of the vertical axis. The exhaust valve is closed when curve 404 is at a lower level near the horizontal axis. The horizontal axis represents time, with time increasing from the left side of the curve to the right side.

[0040] The third course from the top Fig. Figure 4 shows the engine operating state over time. The engine can rotate forward and burn air and fuel when curve 406 is at an "ON" level on the vertical axis. The engine is stopped and not rotating when curve 406 is at an "OFF" level on the vertical axis. The engine rotates in reverse without burning air and fuel when curve 406 is at a "REV." level on the vertical axis. The horizontal axis represents time, with time increasing from the left side of the curve to the right.

[0041] The fourth course from the top Fig. Figure 4 shows the BPF differential pressure (e.g., delta) over time. The vertical axis represents the BPF differential pressure output (e.g., the differential pressure) of the [unclear text]. Fig. Figure 1 shows the exhaust gas sensor 38, where the differential pressure increases in the direction of the arrow on the vertical axis. The horizontal axis represents time, with time increasing from the left side of the curve to the right side. The BPF differential pressure is zero when curve 408 is close to the horizontal axis.

[0042] The fifth path from the top Fig. Figure 4 shows the exhaust gas sensor's impairment status over time. The vertical axis represents the exhaust gas sensor's impairment status, with impairment indicated when curve 410 is at a higher level near the vertical axis arrow. No impairment is indicated when curve 410 is at a lower level near the horizontal axis. The horizontal axis represents time, with time increasing from the left side of the curve to the right.

[0043] At time T0, the engine is switched on and running (e.g., burning air and fuel), the exhaust gas sensor diagnostics are not requested, and the exhaust valve is open. Furthermore, the differential pressure at the BPF is at a lower level, and no exhaust gas sensor malfunction is indicated.

[0044] At time T1, the engine stops and the differential pressure at the BPF begins to decrease. The exhaust gas sensor diagnostics are not requested and the exhaust valve remains open. No exhaust gas sensor malfunction is indicated.

[0045] At time T2, an exhaust gas sensor diagnostic is requested, as indicated by curve 402 rising to a higher level. An exhaust gas sensor diagnostic can be requested after a limit value for a certain time or distance traveled by the vehicle has been exceeded. Furthermore, an exhaust gas sensor diagnostic can be requested while the engine is stopped if it was not performed while the engine was running for a certain limit value. For example, if the exhaust valve did not open or close within a limit value, the exhaust gas sensor diagnostic can be performed when the engine is not running. The exhaust valve remains open, and the engine remains off. The differential pressure at the BPF is zero, and no exhaust gas sensor malfunction is indicated.

[0046] Between time T2 and time T3, the vehicle operating conditions do not change, and the exhaust gas sensor diagnostics do not begin. The exhaust gas sensor diagnostics may be delayed after the engine is stopped to allow vehicle occupants to leave the area and avoid disturbing them during the diagnostics.

[0047] At time T3, the exhaust gas sensor diagnostics begin, and the engine is rotated in reverse. The engine can be rotated via the starter motor 96 or the DISG 240. The engine is rotated without fuel being supplied. The exhaust valve is closed, and the exhaust gas sensor diagnostic status remains confirmed. Closing the exhaust valve can increase the resistance between ambient pressure and a downstream side of the BPF 71 if the downstream hose is connected to the exhaust system and the exhaust gas sensor 38, thus reducing the differential pressure at the BPF. However, if the downstream hose is not connected to the exhaust system and the exhaust gas sensor, there is a low-resistance path to the BPF inlet, so a pressure drop on the upstream side 38A of the exhaust gas pressure sensor can be more significant. The differential pressure at the BPF begins to increase as the airflow through the engine increases due to engine rotation.The exhaust gas sensor is not showing as faulty. Furthermore, the engine intake throttle is open (not shown).

[0048] Between time points T3 and T4, the differential pressure increases to a higher level and then stabilizes. The pressure differential is queried by control unit 12 near time point T3, after it has stabilized, and the queried value is stored in memory. The exhaust gas sensor diagnostic status remains confirmed, and the exhaust valve remains closed. The engine continues to rotate in reverse, and no exhaust gas sensor malfunction is indicated.

[0049] At time T4, the exhaust valve opens and the engine continues to rotate in reverse. Opening the exhaust valve reduces the resistance between ambient pressure and the downstream side of the BPF 71. If the downstream hose 38D is connected to the exhaust gas sensor 38 and the exhaust system 39, a larger differential pressure may be observed by the exhaust gas sensor 38. Likewise, if the downstream hose 38D is disconnected from the exhaust system 39 or exhaust gas sensor 38, the differential pressure observed by the exhaust gas sensor 38 may be larger because ambient pressure is present on the downstream side of the BPF, which can increase the pressure drop across the BPF. No exhaust gas sensor malfunction is indicated.

[0050] Between time T4 and time T5, the differential pressure decreases slightly and then stabilizes. The pressure differential is queried by control unit 12 near time T5, after it has stabilized, and the queried value is stored in memory. The differential pressure queried shortly before time T4 is compared with the differential pressure queried shortly before time T5. The exhaust gas sensor diagnostic status remains confirmed, and the exhaust valve remains closed. The engine continues to rotate in reverse, and no exhaust gas sensor malfunction is indicated.

[0051] At time T5, the control unit 12 determines that the differential pressure change between just before time T4 and just before time T5 is below a threshold value. Consequently, it is assessed that an exhaust gas sensor malfunction has occurred, and this malfunction is confirmed. However, had the differential pressure changed by more than the threshold value, this would indicate a pressure change due to the flow through the BPF, which can be expected when the flow through the engine and exhaust is high and the downstream hose between the exhaust gas sensor 38 and the exhaust system 39 is connected. The engine is stopped, and the differential pressure begins to decrease. The engine throttle is also closed (not shown). Shortly after time T5, the exhaust gas sensor diagnosis is withdrawn, although the malfunctioning condition of the exhaust gas sensor remains confirmed.

[0052] Only with reference to Fig. 5A-5C demonstrates a method for operating a vehicle. The method can be at least partially described as being contained in the memory of the control system in the system consisting of Fig. 1 and Fig. Two stored executable instructions are implemented. Furthermore, the procedure can include measures taken in the real world to determine an operating state of the system from the Fig. 1 and Fig. 2 to change. Additionally, the procedure can change the in Fig. Provide the operating sequence shown in section 4.

[0053] In procedure 502, a process determines 500 vehicle operating conditions. The vehicle operating conditions can be determined by receiving inputs, as in Fig. 1 and Fig. 2 shown, into the control 12. The vehicle operating conditions may include, among other things, the vehicle speed, engine speed, engine torque, driver-demand torque, operating state of the powertrain release clutch, miles traveled by the vehicle, transmission operating state, powertrain release clutch engagement pressure, DISG speed, DISG torque, and ambient temperature. Procedure 500 proceeds to 504 after the vehicle operating conditions have been determined.

[0054] In case 504, procedure 500 assesses whether an exhaust gas sensor diagnosis is desired. An exhaust gas sensor diagnosis may be desired at predetermined intervals, such as after the vehicle has driven a predetermined distance or after a predetermined time. Furthermore, in some examples, an exhaust gas sensor diagnosis may be requested in response to an output from the exhaust gas sensor. If procedure 500 assesses that an exhaust gas sensor diagnosis is desired, the response is Yes, and procedure 700 proceeds to 506. Otherwise, the response is No, and procedure 500 proceeds to 599.

[0055] At 599, procedure 500 operates the engine by burning air and fuel while the engine is rotated in one direction, clockwise. Procedure 500 also deposits particulate matter from the engine in a BPF and regenerates the BPF periodically in response to an output from the exhaust gas sensor (e.g., sensor 38 in Fig. 1) Procedure 500 is coming to an end.

[0056] In procedure 500, procedure 506 assesses whether the vehicle has an exhaust valve (e.g., the one in Fig. The procedure includes the exhaust valve shown (73). Procedure 500 may include a variable stored in memory that indicates whether or not the vehicle includes an exhaust valve. The exhaust valve may be included to provide the vehicle with a powerful sound when the exhaust valve is open and a muted sound when the exhaust valve is closed. If procedure 500 determines that the vehicle includes an exhaust valve, the answer is yes, and procedure 500 proceeds to 540. Otherwise, the answer is no, and procedure 500 proceeds to 508.

[0057] In procedure 508, the procedure can determine whether the vehicle is switched off or not. It can determine that the vehicle is switched off if a vehicle transponder is within a predetermined distance of the vehicle or if an ignition key has been removed from the vehicle. The engine is stopped and the vehicle is not moving when the vehicle is switched off. If procedure 500 determines that a vehicle is switched off, it proceeds to procedure 510. Otherwise, it returns to procedure 504. In some examples, procedure 500 may also require that the vehicle be switched off for a predetermined time before proceeding to procedure 510. Furthermore, procedure 500 may also require that vehicle occupants have left the vehicle before it can proceed to procedure 510.

[0058] At 510, procedure 500 closes the engine intake throttle. The intake throttle can be closed while the engine is running to reduce the flow through the engine so that only a small pressure drop at the BPF is observed by the exhaust gas sensor, even though the engine is running. Procedure 500 then transitions to 512.

[0059] At 512, procedure 500 begins to rotate the engine in reverse. By rotating the engine in reverse, the amount of air pumped through the engine can be increased. Furthermore, the amount of energy required to rotate the engine can be reduced. The engine can be started via a starter (e.g., 96 from Fig. 1) or a DISG (e.g. 240 from Fig. 2) be rotated backwards. No fuel is supplied to the engine while it is rotated in a reverse direction. Procedure 500 transitions to 514.

[0060] At 514, the procedure 500 measures the output of the exhaust gas sensor (e.g., 38 from Fig. 1) and stores the measured output in the controller's memory. Procedure 500 may wait a predetermined time before measuring the exhaust gas sensor output to allow operating conditions to stabilize. Because the engine intake throttle is closed, the differential pressure measured by the exhaust gas sensor should be lower, regardless of whether the exhaust gas sensor hoses are connected to the exhaust system as expected. Procedure 500 proceeds to 516 after querying the exhaust gas pressure sensor.

[0061] At 516, procedure 500 opens the engine intake throttle. Opening the engine intake throttle should increase the airflow through the engine and the BPF, causing an increase in the differential pressure at the BPF if the exhaust gas sensor is properly coupled to the exhaust system. If a downstream hose (e.g., 38D in Fig. 1) If the differential pressure is separated, the differential pressure increase may be lower because the downstream side of the differential pressure sensor is exposed to ambient pressure and because the upstream side of the differential pressure sensor may be closer to ambient pressure. Method 500 transitions to 518.

[0062] At 518, procedure 500 measures the output of the exhaust gas sensor (e.g., 38 from Fig. 1) and stores the measured output in the controller's memory. Procedure 500 may wait a predetermined time before measuring the exhaust gas sensor output to allow operating conditions to stabilize. Because the engine intake throttle is open, the differential pressure measured by the exhaust gas sensor should be high unless the downstream hose of the exhaust gas sensor is disconnected from the exhaust system. If the downstream hose is disconnected from the exhaust system, the differential pressure observed by the exhaust pressure sensor should be lower than if the downstream hose were connected to the exhaust system under the same conditions. Procedure 500 proceeds to 520.

[0063] At step 520, procedure 500 stops the engine rotation and closes the engine intake throttle. By adjusting the engine speed, less current can be drawn from the vehicle battery. Procedure 500 then transitions to step 522.

[0064] In procedure 522, procedure 500 assesses whether the magnitude of the pressure difference between the differential pressure output from the exhaust gas sensor while the engine throttle was closed and the differential pressure output from the exhaust gas sensor after the engine throttle was opened exceeds a threshold value for the pressure difference. If yes, the answer is yes, and procedure 500 proceeds to 530. If no, the answer is no, and procedure 500 proceeds to 524.

[0065] At 530, procedure 500 indicates no exhaust gas sensor malfunction. Procedure 500 cannot confirm exhaust gas sensor malfunction if it is determined that the differential pressures are at a desired level during the diagnosis. Procedure 500 then proceeds to 532.

[0066] At 532, procedure 500 adjusts the engine operating limits so that full engine power and speeds are available. Procedure 500 then terminates.

[0067] At 524, procedure 500 indicates an exhaust gas sensor malfunction. Procedure 500 can indicate an exhaust gas sensor malfunction by illuminating a light, changing the value of a variable in the controller's memory, or providing a visual display via a human-machine interface. Procedure 500 then proceeds to 526.

[0068] In the case of procedure 526, procedure 500 adjusts the engine operating limits to provide reduced engine power and speeds. For example, procedure 500 can reduce an engine power limit so that the engine can deliver 70% of its full power when a sensor malfunction is present. In other examples, engine power cannot be limited, but particulate filter regeneration can be provided more frequently. For example, the vehicle's particulate filter can be regenerated every 500 km instead of every 1000 km by increasing the particulate filter temperature. Increasing the frequency of particulate filter regeneration reduces the possibility of a large amount of carbon-containing substances accumulating in the particulate filter. Procedure 500 then terminates.

[0069] At 540, procedure 500 assesses whether the exhaust valve (e.g., 73 in) Fig. 1) is in an open or closed state. For example, a variable in the controller's memory can indicate the state of the exhaust valve. If procedure 500 judges that the exhaust valve is closed, the answer is yes, and procedure 500 proceeds to 542. Otherwise, the answer is no, and procedure 500 proceeds to 546.

[0070] In procedure 542, procedure 500 determines a differential pressure indicated by the exhaust pressure sensor. For example, procedure 500 can determine the differential pressure by querying the output of the exhaust valve after the engine has been operated for a predetermined time at a predetermined engine speed and load. For instance, procedure 500 can query the output of the differential pressure sensor after the engine has been operated for at least 3 seconds at 1600 rpm and a torque of 100 Nm. Procedure 500 then proceeds to 544.

[0071] In procedure 544, procedure 500 assesses whether the time elapsed since the exhaust valve was last opened and the differential pressure was last read from the exhaust gas sensor exceeds a limit. For example, if the time limit is twenty minutes and it has been two hours since the exhaust valve was opened and the differential pressure output of the exhaust gas sensor was read, while the engine was running at the predetermined engine speed and load described in 542, it can be determined that the answer is yes and procedure 500 proceeds to 570.However, if the exhaust valve was opened less than twenty minutes before the exhaust gas sensor was queried while the engine was running at the predetermined speed and load mentioned in 542, and the exhaust gas sensor was queried while the engine was running at the predetermined engine speed and load described in 542, the answer is No, and Procedure 500 proceeds to 550. If the time elapsed since the last time the exhaust valve was opened and the exhaust gas sensor was queried at the predetermined engine speed and load described in 546 exceeds a certain limit, the answer is Yes, and Procedure 500 proceeds to 570. Otherwise, the answer is No, and Procedure 500 proceeds to 550.

[0072] Accordingly, step 544 may require the exhaust valve to open and close to verify the operation of the exhaust gas sensor within a specified time limit. Such verification can be useful if the exhaust valve is manually controlled. Furthermore, it may be desirable to disable automatic adjustment of the exhaust valve position when an exhaust gas sensor diagnostic is requested, so as not to disturb the vehicle occupants with intrusive monitoring.

[0073] In procedure 546, method 500 determines a differential pressure indicated by the exhaust pressure sensor. For example, method 500 can determine the differential pressure by querying the output of the exhaust valve after the engine has been operated for a predetermined time at a predetermined engine speed and load. Method 500 can, for instance, query the output of the differential pressure sensor if the engine has been operated for at least 3 seconds at 1600 rpm and a torque of 100 Nm. Method 500 then proceeds to 548.

[0074] In 548, procedure 500 assesses whether the time elapsed since the exhaust valve was last closed and the differential pressure was queried from the exhaust gas sensor exceeds a limit. For example, if the time limit is twenty minutes and it has been two hours since the exhaust valve was last closed and the differential pressure output of the exhaust gas sensor was queried, while the engine was running at the predetermined engine speed and load described in 542, it can be determined that the answer is yes and procedure 500 proceeds to 570.However, if the exhaust valve was closed less than twenty minutes before the exhaust gas sensor was queried while the engine was running at the predetermined speed and load mentioned in 542, and the exhaust gas sensor was queried while the engine was running at the predetermined engine speed and load described in 542, the answer is No, and Procedure 500 proceeds to 550. If the time elapsed since the last time the exhaust valve was closed and the exhaust gas sensor was queried at the predetermined engine speed and load described in 546 exceeds a certain threshold, the answer is Yes, and Procedure 500 proceeds to 570. Otherwise, the answer is No, and Procedure 500 proceeds to 550.

[0075] Accordingly, step 548 may require the exhaust valve to open and close to verify the operation of the exhaust gas sensor within a specified time limit. Such a check can be useful if the exhaust valve is manually controlled.

[0076] At 550, procedure 500 determines a difference between the output of the exhaust gas sensor while the exhaust valve is open and the engine is operating at the predetermined speed and load, and the output of the exhaust gas sensor while the exhaust valve is closed and the engine is operating at the predetermined speed and load. Procedure 500 then proceeds to 552.

[0077] In procedure 500, step 552 assesses whether the magnitude of a pressure difference between the differential pressure output from the exhaust gas sensor while the exhaust valve was closed and the differential pressure output from the exhaust gas sensor while the exhaust valve was open exceeds a pressure difference limit. If yes, the answer is yes, and procedure 500 proceeds to step 554. If no, the answer is no, and procedure 500 proceeds to step 558.

[0078] In case 554, procedure 500 indicates no exhaust gas sensor malfunction. Procedure 500 cannot confirm exhaust gas sensor malfunction if it is determined that the differential pressures are at a desired level during the diagnosis. Procedure 500 then proceeds to 556.

[0079] At 556, procedure 500 adjusts the engine operating limits so that full engine power and speeds are available. Procedure 500 then terminates.

[0080] At 558, procedure 500 indicates an exhaust gas sensor malfunction. Procedure 500 can indicate an exhaust gas sensor malfunction by illuminating a light, changing the value of a variable in the controller's memory, or providing a visual display via a human-machine interface. Procedure 500 then proceeds to 560.

[0081] At 560, procedure 500 adjusts the engine operating limits to provide reduced engine power and speeds. For example, procedure 500 can reduce the engine power limit so that the engine can deliver 70% of its full power when a sensor malfunction is present. In other examples, engine power may not be limited, but more frequent particulate filter regeneration may be provided. For instance, the vehicle's particulate filter may be regenerated every 500 km instead of every 1000 km by increasing the particulate filter temperature. Increasing the frequency of particulate filter regeneration reduces the potential for a large accumulation of carbon-containing substances in the particulate filter. Procedure 500 then terminates.

[0082] In 570, procedure 500 assesses whether the vehicle is switched off or not. The vehicle may be considered switched off if the vehicle's engine is stopped, the vehicle is stationary, and a key or other device is located outside a predetermined area of ​​the vehicle. Furthermore, the vehicle may be considered switched off if there are no longer any occupants in the vehicle. In addition, in some examples, procedure 500 may require that a predetermined time has elapsed since the vehicle was switched off before procedure 500 proceeds to 572. If procedure 500 assesses that a vehicle is switched off, it proceeds to 572. Otherwise, procedure 500 terminates.

[0083] In this way, procedure 500 can attempt to diagnose the exhaust gas sensor operation when the vehicle is operational, but if the exhaust valve does not open and close in a timely manner when the engine is operated at a desired engine speed and load, the exhaust gas sensor diagnosis may be delayed until the vehicle is switched off.

[0084] At 572, procedure 500 opens the engine intake throttle and closes the exhaust valve. The intake throttle can open while the engine is running and the exhaust valve is closed because the muffler reduces the flow through the engine and BPF, allowing a small pressure drop at the BPF. Procedure 500 then proceeds to 574.

[0085] At 574, procedure 500 begins to rotate the engine in reverse. By rotating the engine in reverse, the amount of air pumped through the engine can be increased. Furthermore, the amount of energy required to rotate the engine can be reduced. The engine can be started via a starter (e.g., 96 from Fig. 1) or a DISG (e.g. 240 from Fig. 2) be rotated backwards. No fuel is supplied to the engine while it is rotated in a reverse direction. Procedure 500 transitions to 576.

[0086] At 576, the procedure 500 measures the output of the exhaust gas sensor (e.g., 38 from Fig. 1) and stores the measured output in the controller's memory. Procedure 500 may wait a predetermined time before measuring the exhaust gas sensor output to allow operating conditions to stabilize. Because the engine intake throttle is closed, the differential pressure measured by the exhaust gas sensor should be lower, regardless of whether the exhaust gas sensor hoses are connected to the exhaust system as expected. Procedure 500 proceeds to 578 after querying the exhaust gas pressure sensor.

[0087] At 578, procedure 500 opens the exhaust valve. Opening the exhaust valve should increase the airflow through the engine and BPF due to the lack of resistance across the muffler, causing an increase in differential pressure at the BPF if the exhaust gas sensor is properly coupled to the exhaust system. If a downstream hose (e.g., 38D in Fig. 1) If the differential pressure is separated, the differential pressure increase may be lower because the downstream side of the differential pressure sensor is exposed to ambient pressure and because the upstream side of the differential pressure sensor may be closer to ambient pressure. Method 500 transitions to 580.

[0088] At 580, the procedure 500 measures the output of the exhaust gas sensor (e.g., 38 from Fig.1) and stores the measured output in the controller's memory. Procedure 500 may wait a predetermined time before measuring the exhaust gas sensor output to allow operating conditions to stabilize. Because the engine intake throttle is open, the differential pressure measured by the exhaust gas sensor should be high unless the downstream hose of the exhaust gas sensor is disconnected from the exhaust system. If the downstream hose is disconnected from the exhaust system, the differential pressure observed by the exhaust pressure sensor should be lower than if the downstream hose were connected to the exhaust system under the same conditions. Procedure 500 proceeds to 582.

[0089] At step 582, procedure 500 stops the engine rotation and closes the engine intake throttle. Procedure 500 also returns the exhaust valve to the position it was in when the vehicle was initially switched off. By adjusting the engine rotation, less current can be drawn from the vehicle battery. Procedure 500 then proceeds to step 584.

[0090] In procedure 500, step 584 assesses whether the magnitude of a pressure difference between the differential pressure output from the exhaust gas sensor while the exhaust valve was closed and the differential pressure output from the exhaust gas sensor after the exhaust valve was opened exceeds a pressure difference limit. If yes, the answer is yes, and procedure 500 proceeds to step 586. If no, the answer is no, and procedure 500 proceeds to step 590.

[0091] In case 586, procedure 500 indicates no exhaust gas sensor malfunction. Procedure 500 cannot confirm exhaust gas sensor malfunction if it is determined that the differential pressures are at a desired level during the diagnosis. Procedure 500 then proceeds to 588.

[0092] At 588, procedure 500 adjusts the engine operating limits so that full engine power and speeds are available. Procedure 500 then terminates.

[0093] At 590, procedure 500 indicates an exhaust gas sensor malfunction. Procedure 500 can indicate an exhaust gas sensor malfunction by illuminating a light, changing the value of a variable in the controller's memory, or providing a visual display via a human-machine interface. Procedure 500 then proceeds to 592.

[0094] In procedure 500, process 592 adjusts the engine operating limits to provide reduced engine power and speeds. For example, process 500 can reduce the engine power limit so that the engine can deliver 70% of its full power when a sensor malfunction is present. In other examples, engine power cannot be limited, but particulate filter regeneration can be provided more frequently. For example, the vehicle's particulate filter can be regenerated every 500 km instead of every 1000 km by increasing the particulate filter temperature. Increasing the frequency of particulate filter regeneration reduces the possibility of a large amount of carbon-containing substances accumulating in the particulate filter. Process 500 then terminates.

[0095] According to this, Procedure 500 provides a vehicle operating procedure that includes: rotating an engine in reverse without supplying fuel to the engine in response to a diagnostic request from an exhaust system sensor; receiving data from a differential pressure sensor to a controller while the engine is being rotated in reverse; and adjusting engine operation via the controller in response to the data from the differential pressure sensor. The procedure includes the regeneration of a particulate filter as part of adjusting engine operation. The procedure includes the limitation of engine power output as part of adjusting engine operation. The procedure further includes closing an engine intake throttle valve while the engine is being rotated in reverse. The procedure further includes opening an engine intake throttle valve while the engine is being rotated in reverse.The method further comprises opening an intake throttle valve and closing an exhaust valve while the engine is rotated in reverse. The method further comprises opening an intake throttle valve and opening an exhaust valve while the engine is rotated in reverse. The method includes adjusting the engine operation via the control unit in response to data from the differential pressure sensor, and adjusting the engine operation when the differential pressure sensor data indicates that the pressure change between a first condition, where an exhaust valve is open, and a second condition, where the exhaust valve is closed, falls below a threshold value.The procedure involves adjusting the engine operation via the control unit in response to the data from the differential pressure sensor, but not adjusting the engine operation when the data from the differential pressure sensor indicates that the pressure change between the first condition, where the exhaust valve is open, and the second condition, where the exhaust valve is closed, exceeds a limit.

[0096] Procedure 500 also provides a vehicle operating procedure that includes: in response to an exhaust system diagnostic request, measuring a pressure drop across a particulate filter located downstream of an engine while air and fuel are being burned in the engine, both when an exhaust valve is open and when the exhaust valve is closed; and measuring the pressure drop across the particulate filter when no air and fuel are being burned in the engine, and rotating the engine in a reverse direction in response to the sensor diagnostic request and the exhaust valve remaining in its state for a limit time while the engine is burning air and fuel. The procedure further includes comparing a pressure drop across the particulate filter when the exhaust valve is closed with a pressure drop across the particulate filter when the exhaust valve is open.The procedure further includes adjusting the operation of an engine in response to comparing the pressure drop at the particulate filter when the exhaust valve is closed with a pressure drop at the particulate filter when the exhaust valve is open.

[0097] It should be noted that the control and estimation processes contained herein can be used with various engine and / or vehicle system configurations. Furthermore, the procedures described herein can be a combination of actions taken by a controller in the physical world and instructions within the controller. At least portions of the control procedures and routines disclosed herein can be stored as executable instructions in non-volatile memory and executed by the control system, which includes the controller in combination with the various sensors, actuators, and other internal combustion engine hardware. The specific routines described herein can represent one or more from any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like.Accordingly, various illustrated actions, operations, and / or functions can be performed in the illustrated sequence or in parallel, or in some cases, omitted. Likewise, the processing sequence is not strictly necessary to achieve the features and advantages of the exemplary implementations described here, but is provided for easier illustration and description. One or more of the illustrated actions, operations, and / or functions can be performed repeatedly, depending on the specific strategy employed.Furthermore, the described actions, operations and / or functions can graphically represent code to be programmed in a non-volatile memory of the computer-readable storage medium in the engine control system, wherein the described actions are carried out by executing the instructions in a system comprising the various engine hardware components in combination with the electronic control.

[0098] This concludes the description. Upon reading it by a person skilled in the art, many changes and modifications become apparent, without deviating from the spirit and scope of the description. For example, the present description could be advantageously used for I3, I4, I5, V6, V8, V10, and V12 engines operating on natural gas, gasoline, diesel, or alternative fuel configurations.

Claims

[1] Vehicle operating procedures, including: as a response to a diagnostic request from an exhaust system sensor, rotating an engine in a reverse direction without supplying fuel to the engine; Receiving data from a differential pressure sensor to a controller while the engine is being rotated in reverse, and Adjusting the engine operation via the control unit in response to data from the differential pressure sensor. [2] The method according to claim 1, wherein the stopping of the engine operation includes the regeneration of a particulate filter. [3] The method according to claim 1, wherein the stopping of the motor operation includes limiting a motor power output. [4] The method according to claim 1, further comprising closing an engine intake throttle valve while the engine is rotated in the reverse direction. [5] The method according to claim 1, further comprising opening an engine intake throttle valve while the engine is rotated in the reverse direction. [6] The method according to claim 1, further comprising opening an engine intake throttle valve and closing an exhaust valve while the engine is rotated in the reverse direction. [7] The method according to claim 1, further comprising opening an engine intake throttle valve and opening an exhaust valve while the engine is rotated in the reverse direction. [8] Method according to claim 1, wherein adjusting the engine operation via the control in response to the data from the differential pressure sensor includes adjusting the engine operation when the data from the differential pressure sensor indicates that a pressure change between a first condition in which an exhaust valve is open and a second condition in which the exhaust valve is closed falls below a limit value. [9] Method according to claim 8, wherein adjusting the engine operation via the control in response to the data from the differential pressure sensor does not include adjusting the engine operation when the data from the differential pressure sensor indicates that the pressure change between the first condition, where the exhaust valve is open, and the second condition, where the exhaust valve is closed, exceeds a limit value. [10] System, encompassing: a vehicle that includes an internal combustion engine; an engine that is selectively coupled to the internal combustion engine; and a control system that includes executable instructions stored in non-volatile memory to rotate the internal combustion engine in a reverse direction via the engine without burning air and fuel in response to an exhaust gas sensor diagnostic request, as well as instructions to propel the vehicle via the engine. [11] System according to claim 10, further comprising additional instructions for burning air and fuel in the internal combustion engine and for rotating the internal combustion engine in a forward direction. [12] System according to claim 10, further comprising a particulate filter and an exhaust valve located in an exhaust system coupled to the internal combustion engine, wherein the exhaust valve is located downstream of the particulate filter. [13] System according to claim 10, further comprising additional instructions to open and close the exhaust valve while the internal combustion engine is rotated in reverse. [14] System according to claim 10, further comprising a differential pressure sensor configured to detect pressure on two opposite sides of the particle filter. [15] System according to claim 14, further comprising additional instructions to compare the output of the differential pressure sensor with the outlet valve open with the output of the differential pressure sensor with the outlet valve closed.

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