Fault diagnosis method and device for oil tank isolation valve, electronic equipment and vehicle

Abstract

The invention discloses a fault diagnosis method and device for an oil tank isolation valve, electronic equipment and a vehicle, and can determine a second pressure change value of an oil tank by opening the oil tank isolation valve and carrying out carbon tank regeneration operation in response to the fact that a first pressure change value of the oil tank is smaller than a first threshold value, the carbon tank regeneration operation is determined by executing the oil tank pressure relief operation, the carbon tank regeneration operation comprises carbon tank washing or carbon tank desorption, then fault diagnosis is carried out on the oil tank isolation valve according to the second pressure change value, that is, whether the oil tank isolation valve breaks down or not is rapidly determined through the first pressure change value, the diagnosis time is shortened, and the fault type can be accurately identified. The carbon tank can be flushed under the condition that the oil tank isolation valve is opened, then the pressure change value of the oil tank before and after the carbon tank is flushed is monitored to accurately recognize faults of the oil tank isolation valve, and therefore effective diagnosis of the faults of the oil tank isolation valve is achieved.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and specifically relates to a fault diagnosis method, device, electronic equipment and vehicle for a fuel tank isolation valve. Background Art

[0002] In the field of vehicle technology, the Fuel Tank Vapor Inerting (FTIV) system is crucial for reducing exhaust emissions and improving environmental performance. The reliable operation of the FTIV valve in the FTIV system is crucial to the vehicle's fuel efficiency and environmental performance. It ensures efficient fuel use by controlling tank pressure and the emission of evaporated gases. However, over long-term use, the FTIV valve is prone to failure, potentially leading to tank pressure imbalances and, in turn, impacting vehicle smoothness and environmental performance. Traditional FTIV valve fault diagnosis technology has limitations in accuracy, responsiveness, and adaptability. Therefore, achieving rapid and effective FTIV valve fault diagnosis is an urgent challenge facing related technologies. Summary of the Invention

[0003] The embodiments of the present application provide a method, device, electronic equipment, and vehicle for diagnosing a fault of a fuel tank isolation valve, which can solve the problem in related technologies that it is impossible to quickly and effectively diagnose FTIV valve faults.

[0004] In a first aspect, an embodiment of the present application provides a method for diagnosing a fault of a fuel tank isolation valve, the method comprising: in response to a first pressure change value of the fuel tank being less than a first threshold value, determining a second pressure change value of the fuel tank by opening the fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister desorption; and performing a fault diagnosis on the fuel tank isolation valve according to the second pressure change value.

[0005] Optionally, diagnosing the fuel tank isolation valve fault based on the second pressure change includes determining that the fuel tank isolation valve has a stuck-closed fault in response to the second pressure change being less than a second threshold. In this embodiment, the second pressure change allows for rapid determination of the FTIV valve's state. If the second pressure change is less than the second threshold, the FTIV valve is effectively closed, indicating that the FTIV valve is not opening properly, i.e., a stuck-closed fault exists. In this embodiment, monitoring the pressure change between the fuel tank and the carbon canister allows for more rapid and accurate assessment of the FTIV valve's operating status. If the FTIV valve is faulty, its pressure change will differ from normal. This also optimizes the FTIV valve diagnostic strategy by combining fuel vapor and air flow conditions during canister regeneration. By monitoring the fuel tank pressure change in real time and comparing it with the threshold, it is possible to quickly determine whether the FTIV valve has a stuck-closed fault without requiring a complex diagnostic process, thereby improving diagnostic efficiency.

[0006] Optionally, diagnosing the tank isolation valve fault based on the second pressure change value includes: in response to the second pressure change value being less than a second threshold value, and the second pressure change value being the corresponding pressure change value of the tank from a first moment to a second moment, obtaining a first pressure value and a second pressure value, wherein the first pressure value is the corresponding pressure value of the tank at the second moment, and the second pressure value is the corresponding pressure value of the tank at a third moment, the third moment being greater than the second moment, and the second moment being greater than the first moment; and in response to the second pressure value being greater than the first pressure value, determining that the tank isolation valve has a stuck normally closed fault. In this embodiment, by combining pressure changes and tank pressure values at different moments, the FTIV valve status can be more comprehensively monitored, thereby achieving accurate diagnosis of FTIV valve faults. This approach can avoid misdiagnosis due to factors such as leakage, further optimize the diagnostic process, and improve the accuracy of fault diagnosis.

[0007] Optionally, diagnosing a fault in the fuel tank isolation valve based on the second pressure change value includes: in response to the second pressure change value being greater than or equal to a second threshold, closing the fuel tank isolation valve and performing the canister regeneration operation to determine a third pressure change value in the fuel tank; and diagnosing a fault in the fuel tank isolation valve based on the third pressure change value. In this embodiment, to determine whether the FTIV valve has a stuck-open fault under certain operating conditions, the canister regeneration operation can be performed again with the FTIV valve closed. By monitoring the pressure change in the fuel tank, a more rapid and accurate assessment of whether the FTIV valve has a stuck-open fault can be achieved. If the FTIV valve has a fault, its pressure change will differ from normal conditions. Therefore, by monitoring this pressure change, the fault type of the FTIV valve can be effectively identified. Furthermore, this embodiment optimizes the FTIV valve diagnostic strategy, effectively identifying the fault type of the FTIV valve based on the pressure change values of the fuel tank corresponding to two canister regeneration operations. Furthermore, during the canister regeneration operation, FTIV valve fault diagnosis is also performed in conjunction with the flow of fuel vapor and air, further improving diagnostic accuracy.

[0008] Optionally, diagnosing the tank isolation valve fault based on the third pressure change includes determining that the tank isolation valve has a stuck-open fault in response to the third pressure change being greater than a third threshold. In this embodiment, the third threshold is used to measure fuel tank pressure fluctuations. If the third pressure change is greater than the third threshold, it indicates significant tank pressure fluctuations, indicating that the FTIV valve is not closing properly and is stuck-open. If the third pressure change is less than or equal to the third threshold, it indicates that the tank pressure is relatively stable, indicating that the FTIV valve is closing properly. Therefore, if a stuck-open fault is ruled out, the FTIV valve can be controlled to close, followed by a canister regeneration operation, and then the relationship between the third pressure change and the third threshold can be used to accurately identify whether the FTIV valve has a stuck-open fault. By monitoring the tank pressure change in real time and comparing it with the threshold, the presence of a stuck-open fault in the FTIV valve can be determined relatively quickly without requiring a complex diagnostic process, thereby improving diagnostic efficiency.

[0009] Optionally, diagnosing a fault of the fuel tank isolation valve based on the third pressure change value includes: in response to the third pressure change value being greater than a third threshold value, and the third pressure change value being the pressure change value of the fuel tank from a fourth moment to a fifth moment, obtaining a third pressure value and a fourth pressure value, wherein the third pressure value is the pressure value of the fuel tank at the fifth moment, and the fourth pressure value is the pressure value of the fuel tank at a sixth moment, the sixth moment being greater than the fifth moment, and the fifth moment being greater than the fourth moment; and in response to the fourth pressure value being greater than the third pressure value, determining that the fuel tank isolation valve has a stuck-open fault. In this embodiment, by combining pressure changes and fuel tank pressure values at different moments, the status of the FTIV valve can be more comprehensively monitored, thereby achieving accurate diagnosis of FTIV valve faults, further optimizing the diagnostic process, and improving the accuracy of fault diagnosis.

[0010] Optionally, before determining the first pressure change value by performing the fuel tank pressure relief operation, the method further includes adjusting the vehicle's current operating condition to a low-load condition or a high-load condition. In this embodiment, adjusting the vehicle's current operating condition to a low-load condition or a high-load condition causes the fuel tank pressure level to be relatively low or high, i.e., sufficiently away from atmospheric pressure. This allows accurate detection of changes in the fuel tank pressure after the FTIV valve opens, improving the accuracy of FTIV valve fault diagnosis and enabling more comprehensive monitoring of the FTIV valve status to identify FTIV valve failures, thereby ensuring fuel tank reliability and environmental performance. Furthermore, the high-load condition is more consistent with the engine operating conditions of hybrid vehicles, enabling FTIV valve fault diagnosis using different load conditions for different vehicle models, increasing diagnostic flexibility.

[0011] Optionally, before performing the canister regeneration operation and determining the second pressure change value of the fuel tank, the method further includes adjusting the vehicle's current operating condition to a high-load condition. In this embodiment, before determining the second pressure change value of the fuel tank by opening the fuel tank isolation valve and performing the canister regeneration operation, the vehicle's current operating condition is adjusted to a high-load condition. This ensures that the fuel tank pressure level is relatively high, i.e., sufficiently above atmospheric pressure. This allows accurate detection of changes in the fuel tank pressure after the FTIV valve properly opens. Conversely, if the FTIV valve is stuck or normally closed, the detected change in the fuel tank pressure will be less than a second threshold. This pressure change can then be used to identify a FTIV valve failure, thereby ensuring fuel tank reliability and environmental performance. Furthermore, the high-load condition better aligns with the engine operating conditions of hybrid vehicles, thereby meeting the diagnostic requirements of hybrid vehicles. Before determining the third fuel tank pressure change value by opening the fuel tank isolation valve and performing the carbon canister regeneration operation, the vehicle's current operating condition is adjusted to a high-load condition, resulting in a relatively high fuel tank pressure level, sufficiently above atmospheric pressure. This prevents the FTIV valve from properly closing and detecting any changes in fuel tank pressure. Conversely, if the FTIV valve is stuck open, the fuel tank pressure change can be accurately detected, allowing identification of a FTIV valve failure based on this pressure change, ensuring fuel tank reliability and environmental performance. Furthermore, the high-load condition better aligns with hybrid vehicle engine operating conditions, thus meeting hybrid vehicle diagnostic requirements.

[0012] Optionally, the preset conditions include: the fuel tank pressure is greater than a fourth threshold; no refueling command is detected; the fuel tank temperature is greater than a fifth threshold and less than a sixth threshold; and the fuel tank pressure sensor is in a normal state. In this embodiment, these preset conditions must be met to ensure the normal operation of the pressure relief operation. This ensures that the first pressure change value determined is more accurate, thereby improving the accuracy of FTIV valve fault diagnosis.

[0013] Optionally, the preset conditions further include at least one of the following: the carbon canister desorption vacuum is greater than a seventh threshold; the carbon canister flushing flow integral is greater than an eighth threshold; the fuel level in the fuel tank is less than or equal to a ninth threshold and the fuel level signal is valid; the engine shutdown duration is greater than a tenth threshold; the current vehicle speed is less than an eleventh threshold; the difference between the engine starting water temperature and the ambient temperature is less than a twelfth threshold; and the carbon canister load is less than a thirteenth threshold. In this embodiment, to ensure the accuracy of the diagnostic results, diagnosis can be performed if at least one of the above preset conditions is met in addition to the previous embodiment, thereby further ensuring diagnostic accuracy.

[0014] In a second aspect, an embodiment of the present application provides a fault diagnosis device for a fuel tank isolation valve, which includes: a determination module for determining a second pressure change value of the fuel tank in response to a first pressure change value of the fuel tank being less than a first threshold value by opening the fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister desorption; a diagnosis module for performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value.

[0015] In a third aspect, an embodiment of the present application provides an electronic device comprising a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the method described in the first aspect.

[0016] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the steps of the method described in the first aspect are implemented.

[0017] In a fifth aspect, an embodiment of the present application provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the method described in the first aspect.

[0018] In a sixth aspect, an embodiment of the present application provides a computer program product, which includes at least one computer program, and when the computer program is loaded and executed by a processor, implements the method described in the first aspect.

[0019] In the seventh aspect, an embodiment of the present application provides a vehicle, comprising: a memory and a processor, wherein the memory stores executable program code, the processor is used to call and execute the executable program code, and when the executable program code is executed by the processor, the method described in the first aspect is implemented.

[0020] In an embodiment of the present application, in response to a first pressure change value of the fuel tank being less than a first threshold value, a second pressure change value of the fuel tank is determined by opening the fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister purge. Then, a fault diagnosis of the fuel tank isolation valve is performed based on the second pressure change value, that is, firstly, whether the fuel tank isolation valve has a fault is quickly determined by using the first pressure change value, thereby shortening the diagnosis time. Moreover, under passive enabling conditions, by monitoring the pressure change, it is possible to promptly detect whether the FTIV valve is working as expected. At the same time, in active fault monitoring, the function of the FTIV valve can be detected by controlling its opening and closing, thereby ensuring timely detection of faults. Furthermore, it can avoid misjudgments and missed judgments that may be caused by traditional current signal diagnosis, thereby improving the reliability of fault diagnosis. In order to accurately identify the type of fault, the carbon canister regeneration operation can be performed with the fuel tank isolation valve open, and then the fuel tank pressure change value before and after the carbon canister regeneration operation can be monitored to accurately identify the fault in the fuel tank isolation valve, thereby achieving effective diagnosis of the fuel tank isolation valve fault and improving the diagnosis rate. It can also be performed when the engine is running or under specific working conditions without the need for additional equipment or complicated operations, thereby improving the efficiency of diagnosis. At the same time, this diagnostic method not only reduces the emission of fuel vapor, but also improves fuel economy and the environmental performance of the vehicle.

[0021] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in this application or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technical descriptions. Obviously, the drawings described below are merely embodiments of this application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 A schematic flow chart of a method for diagnosing a fault of a fuel tank isolation valve provided in an embodiment of the present application is shown; Figure 2 A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 3 A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 4 A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 5 A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 6a A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 6b A schematic diagram of a fuel tank pressure change timing provided by an embodiment of the present application is shown; Figure 7a A schematic diagram of a fuel tank pressure change timing provided by an embodiment of the present application is shown; Figure 7b A schematic diagram of the flow of fuel vapor provided by an embodiment of the present application is shown; Figure 7c A schematic diagram of a fuel tank pressure change timing provided by an embodiment of the present application is shown; Figure 8 A schematic flow chart of another method for diagnosing a fault of a fuel tank isolation valve provided in an embodiment of the present application is shown; Figure 9 A schematic structural diagram of a fault diagnosis device for a fuel tank isolation valve provided in an embodiment of the present application is shown; Figure 10 A schematic structural diagram of an electronic device provided in an embodiment of the present application is shown; Figure 11 A structural schematic diagram of a vehicle provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] In the following, in conjunction with the accompanying drawings, a method, device, electronic equipment and vehicle for diagnosing a fault of a fuel tank isolation valve provided by an embodiment of the present application are described in detail through specific embodiments and their application scenarios.

[0026] Figure 1 An embodiment of the present application provides a method for diagnosing a fault in a fuel tank isolation valve. The method can be performed by an electronic device, which may include a server and / or a terminal device. In other words, the method can be performed by software or hardware installed on the electronic device. The method includes the following steps: S110 : In response to a first pressure change value of the fuel tank being less than a first threshold, determining a second pressure change value of the fuel tank by opening a fuel tank isolation valve and performing a carbon canister regeneration operation.

[0027] The first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister desorption.

[0028] S120: Performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value.

[0029] Among them, the fuel tank isolation valve, namely the FTIV valve, is used to manage the pressure in the fuel tank and control the release of fuel vapor in the tank.

[0030] In one exemplary embodiment, before S110, the method may further include: S102: When the preset condition is met, obtaining a fifth pressure value of the fuel tank; S104: Open the fuel tank isolation valve; S106: When the preset time period is satisfied, closing the fuel tank isolation valve and obtaining a sixth pressure value of the fuel tank; S108: Determine that the first pressure change value is the absolute value of the difference between the fifth pressure value and the sixth pressure value.

[0031] For example, Figure 2 As shown in the figure, when the fuel tank pressure relief operation is not performed, the FTIV valve is normally closed, the passage between the fuel tank and the carbon canister is cut off, and the fuel vapor in the fuel tank cannot flow into the carbon canister through the FTIV valve and is sealed in the fuel tank. The activated carbon in the carbon canister will absorb the fuel vapor that has entered before and prevent it from escaping into the atmosphere. It should be noted that Figure 2 In the figure, the fuel vapor in the fuel tank is represented by a black arrow, and the fuel vapor in the carbon canister is represented by a gray arrow. If there are black arrows or gray arrows in other figures, they will not be repeated. In the process of performing the fuel tank pressure relief operation, the FTIV valve is first opened, for example, Figure 3As shown, if the FTIV valve truly responds and opens, the passage between the fuel tank and the canister is opened, allowing fuel vapor in the tank to flow through the FTIV valve into the canister. Once the fuel vapor enters the canister through the FTIV valve, it is adsorbed by the activated carbon in the canister. This flow helps temporarily store the fuel vapor in the canister, preventing it from escaping directly into the atmosphere, thereby meeting environmental protection requirements. At this point, the pressure in the fuel tank gradually approaches atmospheric pressure. As you can understand, the bottom of the canister is typically designed with a vent to allow outside air to enter. This airflow balances the internal pressure, thus maintaining equilibrium with atmospheric pressure. Therefore, when the FTIV valve opens, fuel vapor in the tank enters the canister, causing the internal pressure to increase. However, since the canister is connected to the atmosphere via the vent, the air entering the canister balances the internal pressure. As the internal pressure balances, the pressure in the fuel tank gradually decreases, eventually reaching equilibrium with atmospheric pressure. Therefore, the fuel tank pressure changes significantly before and after the FTIV valve opens. If the first pressure change is greater than a first threshold, it can be determined that the FTIV valve is not faulty, meaning that the FTIV valve has opened normally from a normally closed state. If the FTIV valve is stuck open or not actually opened (i.e., stuck closed), then the fuel tank pressure will not change significantly after the pressure relief operation. Therefore, by monitoring the fuel tank pressure change before and after the pressure relief operation, it is possible to quickly and effectively determine whether the FTIV valve has a fault. Specifically, if the first pressure change is less than the first threshold when pre-set conditions are met, it indicates that the FTIV valve may not be fully open or is not operating normally, indicating that the FTIV valve may be stuck closed or stuck open. This diagnostic method shortens diagnostic time. By monitoring pressure changes, it is possible to promptly determine whether the FTIV valve is operating as expected. It can also be used in active fault monitoring to test the FTIV valve's functionality by controlling its opening and closing, ensuring timely fault detection. In addition, by monitoring the changes in the tank pressure value before and after pressure relief, it is possible to effectively determine whether the FTIV valve has failed. This can also avoid misjudgments and missed judgments that may be caused by traditional current signal diagnosis, thereby improving the reliability of fault diagnosis.

[0032] In order to accurately determine the cause of the FTIV valve failure, a second pressure change value may be further obtained, and the cause of the FTIV valve failure may be determined based on the second pressure change value.

[0033] Among them, the carbon canister desorption operation includes carbon canister flushing or carbon canister desorption. Carbon canister flushing refers to using a strong airflow to flush the fuel vapor in the carbon canister, and allowing the flushing airflow and the desorbed fuel vapor in the carbon canister to re-enter the engine to participate in combustion. Carbon canister desorption means that when the engine is running, the negative pressure generated by the intake manifold guides the fuel vapor adsorbed in the carbon canister into the combustion chamber to participate in combustion. Therefore, when the FTIV valve is opened, the carbon canister regeneration operation is performed, and the carbon canister solenoid valve will also be opened. For example, Figure 4 As shown, the fuel vapor in the fuel tank enters the carbon canister through the FTIV valve. The fuel vapor in the carbon canister is sucked into the intake manifold under the action of the intake manifold. After entering the intake manifold, the fuel vapor mixes with the air coming in through the intake port to form a combustible mixture, which enters the engine to participate in combustion. It should be noted that Figure 4 In the figure, air entering through the air intake is represented by a black dashed arrow and will not be further described. Therefore, when the FTIV valve is open, regenerating the canister will involve the flow of fuel vapor within the tank, which in turn affects the pressure balance of the tank. Therefore, the cause of the FTIV valve failure can be accurately determined by the second pressure change in the tank. This diagnostic method can be performed while the engine is running or under specific operating conditions, without the need for additional equipment or complex operations, thus improving diagnostic efficiency. Furthermore, by monitoring the pressure changes within the tank during the canister regeneration operation to diagnose the FTIV valve, not only can the cause of the failure be identified promptly, but it can also reduce fuel vapor emissions, improving fuel economy and the vehicle's environmental performance.

[0034] In an exemplary embodiment, determining the second pressure change value of the fuel tank includes determining the second pressure change value of the fuel tank in response to a duration of the carbon canister regeneration operation being greater than a first duration.

[0035] It is understood that to improve fault diagnosis accuracy and reduce misdiagnosis due to transient changes, a second pressure change value can be determined after the canister flushing operation has been performed for a duration greater than the first duration. The second pressure change value is determined by the seventh fuel tank pressure value determined before opening the fuel tank isolation valve and the eighth pressure value determined after the canister flushing has been completed. Specifically, the second pressure change value is the absolute difference between the seventh and eighth pressure values. In other words, a longer operation duration allows for more accurate diagnosis of FTIV valve failure, avoiding misdiagnosis due to a too-brief canister regeneration operation. This is because FTIV valve failure diagnosis based solely on short pressure changes can miss detections. For example, if there is a minor leak in the fuel tank or canister piping, even if the FTIV valve is stuck and normally closed, the pressure change may not be noticeable. Therefore, a canister regeneration operation performed for a duration greater than the first duration allows for more comprehensive monitoring of the FTIV valve's operating status, improving diagnostic accuracy and reliability.

[0036] In an embodiment of the present application, in response to a first pressure change value of the fuel tank being less than a first threshold value, a second pressure change value of the fuel tank is determined by opening the fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister purge. Then, a fault diagnosis of the fuel tank isolation valve is performed based on the second pressure change value, that is, firstly, whether the fuel tank isolation valve has a fault is quickly determined by using the first pressure change value, thereby shortening the diagnosis time. That is, by monitoring the pressure change, it is possible to promptly detect whether the FTIV valve is working as expected. At the same time, in active fault monitoring, the function of the FTIV valve can be detected by controlling the opening and closing of the FTIV valve, thereby ensuring timely detection of faults. It can also avoid misjudgments and missed judgments that may be caused by traditional current signal diagnosis, thereby improving the reliability of fault diagnosis. In order to accurately identify the type of fault, the carbon canister regeneration operation can be performed with the fuel tank isolation valve open, and then the fuel tank pressure change value before and after the carbon canister regeneration operation can be monitored to accurately identify the fault in the fuel tank isolation valve, thereby achieving effective diagnosis of the fuel tank isolation valve fault and improving the diagnosis rate. It can also be performed when the engine is running or under specific working conditions without the need for additional equipment or complicated operations, thereby improving the efficiency of diagnosis. At the same time, this diagnostic method not only reduces the emission of fuel vapor, but also improves fuel economy and the environmental performance of the vehicle.

[0037] In an exemplary embodiment, the above-mentioned S120 may include: in response to the second pressure change value being less than a second threshold, determining that the fuel tank isolation valve has a stuck normally closed fault.

[0038] It is understandable that in Figure 1 In the illustrated embodiment, if the first pressure change in the fuel tank is less than a first threshold, it can be determined that the FTIV valve has a stuck-closed fault or a stuck-open fault. In this embodiment, a second threshold is used to measure the fluctuation of the fuel tank pressure. If the second pressure change is less than the second threshold, the fuel tank pressure is relatively stable; if the second pressure change is greater than the second threshold, the fuel tank pressure fluctuates significantly. Therefore, if a FTIV valve fault is determined, the FTIV valve is controlled to open, the carbon canister is regenerated, and the relationship between the second pressure change and the second threshold is used to accurately identify whether the FTIV valve has a stuck-closed fault. By monitoring the fuel tank pressure change in real time and comparing it with the threshold, the presence of a stuck-closed fault in the FTIV valve can be determined relatively quickly without requiring a complex diagnostic process, thus improving diagnostic efficiency.

[0039] When the FTIV valve is controlled to be open, the FTIV valve will actually be in one of the following two states: The first type: Due to the stuck normally open fault of the FTIV valve, the FTIV valve is actually in the open state; The second type: Due to the stuck normally closed fault of the FTIV valve, the FTIV valve is actually in the closed state.

[0040] So: (1) When the FTIV valve is actually in the open state, the regeneration operation is performed. During the operation, the fuel vapor in the carbon canister is pumped out, and the evaporated fuel vapor in the fuel tank is replenished into the carbon canister through the ventilation pipe. The fuel tank pressure will drop briefly. At this time, the outside air can flow into the fuel tank through the vent on the other side of the carbon canister. It can be understood that the bottom of the carbon canister is usually designed with a vent to allow outside air to enter the carbon canister. The entry of outside air can balance the air pressure inside the carbon canister. Therefore, the air pressure inside the carbon canister is kept in balance with the atmospheric pressure. Then, when the FTIV valve is opened, the fuel vapor in the fuel tank will enter the carbon canister, and the fuel vapor inside the carbon canister will be pumped out, and the air pressure in the carbon canister will drop accordingly. However, since the carbon canister is connected to the atmosphere through the vent, the entry of outside air can balance the air pressure inside the carbon canister. As the air pressure inside the carbon canister is balanced, the pressure inside the fuel tank will gradually tend to balance with the atmospheric pressure. Then, since the outside air cannot be quickly replenished to the fuel tank through the carbon canister in a short period of time, the pressure of the fuel tank will not be able to quickly and automatically balance, so the fuel tank will produce pressure fluctuations, and thus the fault diagnosis can be achieved based on the pressure fluctuations. For example, Figure 5 As shown in the figure, if the FTIV valve is actually open, fuel vapor in the fuel tank can flow through the FTIV valve into the carbon canister. During the carbon canister regeneration operation, the fuel vapor in the carbon canister is drawn into the engine intake system through the engine intake manifold and then enters the engine cylinders for combustion. When the fuel vapor in the carbon canister is drawn into the engine, a certain negative pressure is generated inside the carbon canister and in the fuel tank. At this time, outside air enters the carbon canister through the carbon canister vent to balance the pressure. However, outside air cannot quickly pass through the FTIV valve and enter the fuel tank. Therefore, the fuel tank pressure will not automatically balance in a short period of time, and the fuel tank pressure will fluctuate.

[0041] (2) When the FTIV valve is actually in the closed state, the carbon canister regeneration operation is performed. At this time, the fuel tank is in a sealed state. When the external pressure of the fuel tank, that is, the carbon canister pressure, decreases, the internal pressure of the fuel tank will not change directly because there is no gas exchange between the closed fuel tank and the external environment. For example, Figure 6aAs shown in the figure, if the FTIV valve is actually closed, during the canister regeneration operation, the fuel vapor in the fuel tank will not be able to flow into the canister. The fuel vapor in the canister will be drawn into the engine intake system through the engine intake manifold and then enter the engine cylinders for combustion. When the fuel vapor in the canister is drawn into the engine, a certain negative pressure will be generated inside the canister. At this time, outside air will enter the canister through the canister vent to balance the pressure. However, air cannot enter the fuel tank through the FTIV valve. Therefore, the external pressure has no effect on the pressure inside the tank, so the tank pressure remains stable.

[0042] Therefore, the FTIV valve's current state can be quickly determined using the second pressure change. If the second pressure change is less than the second threshold, the FTIV valve is effectively closed, indicating that the valve is not opening properly, indicating a stuck-closed fault. In this embodiment, monitoring the pressure change between the fuel tank and the carbon canister allows for a more rapid and accurate assessment of the FTIV valve's operating status. If the FTIV valve is faulty, its pressure change will differ from normal. This also optimizes the FTIV valve diagnostic strategy, combining the flow of fuel vapor and air during canister regeneration to determine FTIV valve faults.

[0043] In an exemplary embodiment, the fault diagnosis of the oil tank isolation valve based on the second pressure change value includes: in response to the second pressure change value being less than a second threshold value, and the second pressure change value being the pressure change value corresponding to the oil tank from a first moment to a second moment, obtaining a first pressure value and a second pressure value, wherein the first pressure value is the pressure value corresponding to the oil tank at the second moment, the second pressure value is the pressure value corresponding to the oil tank at a third moment, the third moment is greater than the second moment, and the second moment is greater than the first moment; in response to the second pressure value being greater than the first pressure value, determining that the oil tank isolation valve has a stuck normally closed fault.

[0044] In this embodiment, a two-step diagnosis of the FTIV valve can be achieved by combining the second pressure change value with the corresponding tank pressure values at different times. Figure 6b As shown, the second pressure change value is the pressure change of the fuel tank from the first moment to the second moment. At the second moment, if the second pressure change value is less than the second threshold, it means that the FTIV valve may not open normally. To further determine whether the FTIV valve has a stuck normally closed fault, the pressure value of the FTIV valve at the second moment, i.e., the first pressure value, and the pressure value at the third moment, i.e., the second pressure value, can be obtained for secondary diagnosis. For example, continue to refer to Figure 6a and Figure 6b, the FTIV valve is actually closed, and the fuel tank is sealed. When the external tank pressure (i.e., the canister pressure) decreases, the internal tank pressure does not directly change because there is no gas exchange between the closed tank and the external environment. Therefore, at the second moment, the internal tank pressure will remain stable, with the difference from the tank pressure before the canister regeneration operation being zero or less than the second threshold. Over time, the internal tank pressure will continue to increase as fuel evaporates. If the FTIV valve remains stuck closed, then at the third moment, the internal tank pressure (i.e., the second pressure value) will be greater than the first pressure value. This further confirms that the FTIV valve is stuck closed. By combining pressure changes with tank pressure values at different moments, the FTIV valve status can be more comprehensively monitored, enabling accurate diagnosis of FTIV valve faults. This approach avoids misdiagnosis due to factors such as leakage, further optimizes the diagnostic process, and improves the accuracy of fault diagnosis.

[0045] Optionally, the performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value includes: in response to the second pressure change value being greater than or equal to a second threshold, determining that the fuel tank isolation valve does not have a stuck normally closed fault.

[0046] It is understood that the second threshold is used to measure fuel tank pressure fluctuations. If the second pressure change value is less than the second threshold, the fuel tank pressure is relatively stable. If the second pressure change value is greater than the second threshold, the fuel tank pressure fluctuates significantly. During the canister regeneration process, fuel vapor is removed from the canister and then replenished into the canister via the ventilation line. This causes a brief drop in fuel tank pressure. During this time, outside air can flow into the tank through the vent on the other side of the canister. However, since outside air cannot quickly flow through the canister to the tank within a short period of time, the tank pressure cannot automatically balance quickly, resulting in pressure fluctuations. Therefore, if the second pressure change value is greater than or equal to the second threshold, it indicates that the FTIV valve is actually open, meaning that the tank isolation valve does not have a stuck normally closed fault.

[0047] Further, in response to the second pressure change value being greater than or equal to the second threshold, determining that the fuel tank isolation valve does not have a stuck normally closed fault includes: in response to the second pressure change value being greater than or equal to the second threshold, and the second pressure change value being the pressure change of the fuel tank from the first moment to the second moment, obtaining a fourth pressure change value, wherein the fourth pressure change value is the pressure change of the fuel tank from the second moment to the seventh moment; in response to the fourth pressure change value being less than the second pressure change value, determining that the fuel tank isolation valve does not have a stuck normally closed fault, and determining that the fuel tank isolation valve does not have a stuck normally closed fault.

[0048] In this embodiment, further diagnosis of the FTIV valve can be achieved through the pressure change values of the fuel tank corresponding to different moments. Among them, when the FTIV valve is actually in the open state, the carbon canister regeneration operation is performed. During the operation, the fuel vapor in the carbon canister is extracted, and the evaporated fuel vapor in the fuel tank is replenished into the carbon canister through the ventilation pipe. The fuel tank pressure will drop briefly. At this time, the outside air can flow into the fuel tank through the vent on the other side of the carbon canister. However, since the outside air cannot be quickly replenished into the fuel tank through the carbon canister, the pressure of the fuel tank will not be able to automatically balance within the fifth moment, and may even be a negative pressure. Therefore, the fuel tank pressure at the fifth moment during or after the carbon canister regeneration operation is a negative pressure and is less than the fuel tank pressure before the carbon canister regeneration operation. Among them, the fuel tank pressure before this carbon canister regeneration operation is the fuel tank pressure after the pressure relief operation, that is, the atmospheric pressure. At this time, the fuel tank pressure fluctuates greatly. For example, refer to Figure 7a At the second moment, the second pressure change value may be greater than the second threshold value, but after a certain period of time, that is, at the seventh moment, the external air has been added to the fuel tank. At this time, the pressure value in the fuel tank will be consistent with the carbon canister and atmospheric pressure, that is, the pressure value in the fuel tank at the seventh moment will be consistent with the pressure value before the carbon canister regeneration operation. Then, the fourth pressure change value will be less than the second pressure change value. For example, referring to Figure 7b If the FTIV valve is actually open, fuel vapor in the fuel tank can flow through the FTIV valve into the canister. During canister flushing, the fuel vapor in the canister is drawn into the engine's intake system through the engine's intake manifold and subsequently enters the engine cylinders for combustion. When the fuel vapor in the canister is drawn into the engine, a certain negative pressure is generated inside the canister and in the fuel tank. At this point, outside air enters the canister through the canister's vent to equalize the pressure. However, outside air cannot quickly enter the fuel tank through the FTIV valve at the second moment. Therefore, the fuel tank pressure cannot automatically equalize within the second moment, causing pressure fluctuations in the tank. However, by the seventh moment, outside air has gradually replenished the tank, and the tank pressure is consistent with the canister pressure or atmospheric pressure. In other words, if the fourth pressure change value is less than the second pressure change value, the fuel tank isolation valve is determined not to be stuck normally closed.

[0049] It should be noted that the seventh moment and the third moment may be the same moment or different moments.

[0050] In an exemplary embodiment, the above S120 may include the following steps: S122 : In response to the second pressure change value being greater than or equal to a second threshold, determining a third pressure change value of the fuel tank by closing the fuel tank isolation valve and performing the carbon canister regeneration operation.

[0051] S124: Performing fault diagnosis on the fuel tank isolation valve according to the third pressure change value.

[0052] As can be seen from the description of the aforementioned embodiments, if the second pressure change value is less than the second threshold, the FTIV valve is actually closed. Therefore, it can be determined that the FTIV valve has a stuck-closed fault. However, the possibility of a stuck-open fault under certain operating conditions cannot be ruled out. Therefore, to further verify whether the FTIV valve has a stuck-open fault, the canister regeneration operation can be performed again with the FTIV valve closed to obtain a third pressure change value. The third pressure change value can then be used to determine whether the FTIV valve has a stuck-open fault. Regenerating the canister with the FTIV valve closed does not involve the flow of fuel vapor in the fuel tank, which means it does not affect the pressure balance in the fuel tank. Therefore, the third pressure change value can be used to diagnose FTIV valve faults.

[0053] In this embodiment, to determine whether the FTIV valve has a stuck-open fault under certain operating conditions, the canister regeneration operation can be performed again with the FTIV valve closed. By monitoring the pressure change in the fuel tank, a more rapid and accurate assessment of whether the FTIV valve has a stuck-open fault can be made. If the FTIV valve is faulty, its pressure change will differ from normal conditions. Therefore, monitoring this pressure change can effectively identify the type of FTIV valve fault. Furthermore, this embodiment optimizes the FTIV valve diagnostic strategy, effectively identifying the FTIV valve fault type based on the fuel tank pressure change corresponding to two canister regeneration operations. Furthermore, during the canister regeneration operation, the FTIV valve fault diagnosis is also combined with the flow of fuel vapor and air, further improving diagnostic accuracy.

[0054] Furthermore, in another exemplary embodiment, the above S124 may include: in response to the third pressure change value being greater than a third threshold, determining that the FTIV valve has a stuck-open fault.

[0055] It is understandable that in Figure 1 In the illustrated embodiment, if the first pressure change value of the fuel tank is less than a first threshold, it can be determined that the FTIV valve has a stuck-closed fault or a stuck-open fault. In this embodiment, if the FTIV valve is faulty, the FTIV valve is controlled to close and then a carbon canister regeneration operation is performed to accurately identify whether the FTIV valve has a stuck-open fault.

[0056] Assuming the FTIV valve is not faulty, then when the FTIV valve is controlled to be closed, the FTIV valve is actually closed. During the carbon canister regeneration process, the carbon canister solenoid valve is opened, and the fuel vapor in the carbon canister is sucked out. The extracted fuel vapor enters the engine's intake system through the pipeline. At this time, the fuel tank is in a sealed state, and the fuel tank pressure does not change. If the FTIV valve is stuck and normally open, then when the FTIV valve is controlled to be closed, the FTIV valve is actually open. During the carbon canister desorption process, the fuel vapor in the carbon canister is sucked out. The evaporated fuel vapor in the fuel tank is replenished into the carbon canister through the ventilation line. The fuel tank pressure will drop, resulting in negative pressure and pressure fluctuations. Therefore, when the FTIV valve is not faulty, closing the FTIV valve and performing the carbon canister regeneration operation will not cause the pressure in the fuel tank to fluctuate; when the FTIV valve is faulty, after closing the FTIV valve, the FTIV valve is actually in the open state, and then performing the carbon canister desorption operation, the pressure in the fuel tank will fluctuate; therefore, if the third pressure change value is greater than the third threshold, it means that the FTIV valve is actually in the open state, and it can be determined that the FTIV valve has a stuck-open fault. For example, continue to refer to Figure 5 If the FTIV valve is actually in the open state, when the carbon canister regeneration operation is in progress, the fuel vapor in the fuel tank can flow into the carbon canister through the FTIV valve. The fuel vapor in the carbon canister will be sucked into the engine intake system under the action of the engine intake manifold, and then enter the engine cylinder to participate in combustion. When the fuel vapor in the carbon canister is sucked into the engine, a certain negative pressure will be generated inside the carbon canister and in the fuel tank. At this time, the outside air will enter the carbon canister through the air vent of the carbon canister to balance the pressure, but the outside air cannot quickly pass through the FTIV valve into the fuel tank, so the pressure of the fuel tank will not be able to automatically balance in a short period of time, and the fuel tank will experience pressure fluctuations. For example, continue to refer to Figure 6a If the FTIV valve is actually closed during canister regeneration, fuel vapor in the fuel tank will not be able to flow into the canister. Instead, the fuel vapor in the canister will be drawn into the engine's intake system through the engine's intake manifold and then into the engine cylinders for combustion. When the fuel vapor in the canister is drawn into the engine, a certain negative pressure will be generated inside the canister, but this negative pressure will not affect the pressure in the fuel tank. At this time, outside air will enter the canister through the canister's vent to balance the pressure. However, air cannot enter the fuel tank through the FTIV valve, and external pressure will not affect the pressure in the tank, so the tank pressure remains stable.

[0057] In this embodiment, the third threshold is used to measure fuel tank pressure fluctuations. If the third pressure change is greater than the third threshold, it indicates significant tank pressure fluctuations, indicating that the FTIV valve is not closing properly and is stuck open. If the third pressure change is less than or equal to the third threshold, the tank pressure is relatively stable, indicating that the FTIV valve is closing properly. Therefore, if a stuck-closed FTIV valve fault is ruled out, the FTIV valve can be controlled to close, followed by a canister regeneration operation. Based on the relationship between the third pressure change and the third threshold, accurate identification of a stuck-open FTIV valve fault can be achieved. By monitoring the fuel tank pressure change in real time and comparing it with the threshold, the presence of a stuck-open FTIV valve fault can be determined relatively quickly without requiring a complex diagnostic process, improving diagnostic efficiency.

[0058] Further, in another exemplary embodiment, determining the third pressure change value of the fuel tank includes: determining the third pressure change value of the fuel tank in response to an execution time of the carbon canister regeneration operation being greater than a second time.

[0059] It is understandable that in order to improve the accuracy of fault diagnosis and reduce misjudgments caused by instantaneous changes, a third pressure change value can be determined after the execution time of the carbon canister regeneration operation is greater than the second time period, wherein the third pressure change value is determined by the ninth pressure value of the fuel tank determined before closing the FTIV valve and the tenth pressure value after the carbon canister regeneration operation is completed, that is, the third pressure change value is the absolute value of the difference between the ninth pressure value and the tenth pressure value.

[0060] In the embodiment of the present application, the first threshold, the second threshold and the third threshold may be equal or different and may be set according to actual conditions, and the embodiment of the present application does not make any specific limitation.

[0061] In an exemplary embodiment, the fault diagnosis of the fuel tank isolation valve based on the third pressure change value includes: in response to the third pressure change value being greater than a third threshold value, and the third pressure change value being the pressure change value corresponding to the fuel tank from a fourth moment to a fifth moment, obtaining a third pressure value and a fourth pressure value, wherein the third pressure value is the pressure value corresponding to the fuel tank at the fifth moment, the fourth pressure value is the pressure value corresponding to the fuel tank at the sixth moment, the sixth moment is greater than the fifth moment, and the fifth moment is greater than the fourth moment; in response to the fourth pressure value being greater than the third pressure value, determining that the fuel tank isolation valve has a stuck normally open fault.

[0062] In this embodiment, further diagnosis of the FTIV valve can be achieved by combining the third pressure change value with the corresponding fuel tank pressure values at different times. Figure 7cAs shown, the third pressure change value is the pressure change of the fuel tank from the fourth moment to the fifth moment. If the third pressure change value is greater than the third threshold value at the fifth moment, it means that the FTIV valve may not be closed normally. To further determine whether the FTIV valve has a stuck open fault, the pressure value of the FTIV valve at the fifth moment, i.e., the third pressure value, and the pressure value at the sixth moment, i.e., the fourth pressure value, can be obtained for secondary diagnosis. For example, continue to refer to Figure 5 , the FTIV valve is actually in the open state, and the fuel vapor in the fuel tank can flow into the carbon canister through the FTIV valve. When the carbon canister is regenerated, the fuel vapor in the carbon canister will be sucked into the engine intake system under the action of the engine intake manifold, and then enter the engine cylinder to participate in combustion. When the fuel vapor in the carbon canister is sucked into the engine, a certain negative pressure will be generated inside the carbon canister and the fuel tank. Then, at the fifth moment, the pressure value inside the fuel tank is negative pressure and is lower than the pressure value of the fuel tank before the carbon canister regeneration operation, that is, the third pressure change value is greater than the third threshold value. As time goes by, for example, continue to refer to Figure 7b As external air slowly enters the fuel tank through the carbon canister and the FTIV valve, the fuel tank pressure rises until it reaches atmospheric pressure. The fourth pressure value at the sixth moment is greater than the third pressure value at the fifth moment, further confirming a stuck-open FTIV valve fault. By combining pressure changes with tank pressure values at different moments, the FTIV valve's status can be more comprehensively monitored, enabling accurate diagnosis of FTIV valve faults. This further optimizes the diagnostic process and improves the accuracy of fault diagnosis.

[0063] Optionally, diagnosing the fault of the fuel tank isolation valve based on the third pressure change value includes: determining that the fuel tank isolation valve does not have a stuck-open fault in response to the third pressure change value being less than or equal to a third threshold. In this embodiment, the third threshold is used to measure fuel tank pressure fluctuations. A value less than or equal to the third threshold indicates relatively stable fuel tank pressure, while a value greater than the third threshold indicates significant fuel tank pressure fluctuations. When the FTIV valve is closed, regenerating the carbon canister does not affect the flow of fuel vapor within the tank, thus not affecting the tank's pressure balance. Therefore, if the third pressure change value is less than or equal to the third threshold, the FTIV valve is effectively closed, indicating that the fuel tank isolation valve does not have a stuck-open fault.

[0064] In an exemplary embodiment, before determining the first pressure change value by performing the fuel tank pressure relief operation, the method further includes: adjusting the current operating condition of the vehicle to a light load operating condition or a heavy load operating condition.

[0065] A low-load operating condition refers to a condition in which the engine's intake pressure is lower than atmospheric pressure during operation, creating a negative pressure. This can be, for example, when the vehicle's battery is less than a set value and the engine is generating electricity. A high-load operating condition refers to a condition in which the engine's intake pressure is higher than atmospheric pressure during operation, creating a positive pressure. This can be, for example, during a supercharged operating condition.

[0066] It is understandable that in order to diagnose whether there is a fault in the FTIV valve through pressure relief operation, the current operating condition of the vehicle is adjusted to a low-load condition or a high-load condition, so that the switching action of the FTIV valve has a more obvious impact on the fuel tank pressure, that is, the pressure value of the fuel tank changes more significantly.

[0067] When the vehicle's current operating condition is adjusted to a low-load condition, a negative pressure environment is created when the engine is running. This negative pressure can be transmitted to the fuel tank through the fuel system, causing the pressure inside the fuel tank to fall below atmospheric pressure. During the pressure relief operation, the fuel tank pressure will equalize with the carbon canister pressure, and then with atmospheric pressure. During this process, the fuel tank pressure rises from negative pressure to equal atmospheric pressure, and the fuel tank pressure will fluctuate significantly. Therefore, before determining the first pressure change value by performing the fuel tank pressure relief operation, adjusting the vehicle's current operating condition to a low-load condition allows for monitoring of significant pressure changes, thereby improving diagnostic accuracy.

[0068] In hybrid vehicles, low-load operating conditions are rare or only possible under specific conditions. Therefore, to quickly diagnose FTIV valve faults, the vehicle's current operating condition can be adjusted to a high-load condition. This allows for rapid diagnosis of the FTIV valve under high-load conditions. Under high-load conditions, engine operation generates positive pressure, causing the fuel system pressure to rise above atmospheric pressure. This positive pressure also affects the pressure within the fuel tank. Under high-load conditions, the fuel tank pressure is already above atmospheric pressure. Therefore, during the pressure relief operation, the tank pressure will equalize with the canister pressure, and ultimately atmospheric pressure. During this process, the tank pressure drops from positive pressure to atmospheric pressure, resulting in significant fluctuations in the tank pressure. Therefore, before performing the tank pressure relief operation to determine the first pressure change, adjusting the vehicle's current operating condition to a high-load condition allows for monitoring of significant pressure changes, thereby improving diagnostic accuracy.

[0069] In this embodiment, by adjusting the vehicle's current operating condition to a low-load or high-load condition, the fuel tank pressure level will be relatively low or high, that is, sufficiently away from atmospheric pressure. This allows precise detection of changes in the fuel tank pressure after the FTIV valve opens, improving the accuracy of FTIV valve fault diagnosis. This allows for more comprehensive monitoring of the FTIV valve status to identify FTIV valve failures and ensure fuel tank reliability and environmental performance. Furthermore, the high-load condition is more consistent with the engine operating conditions of hybrid vehicles, enabling FTIV valve fault diagnosis based on different load conditions for different vehicle models, increasing diagnostic flexibility.

[0070] In an exemplary embodiment, before performing the carbon canister regeneration operation, the method further includes: adjusting the current operating condition of the vehicle to a high-load operating condition.

[0071] It is understood that before determining the second pressure change in the fuel tank by opening the fuel tank isolation valve and performing the canister regeneration operation, a pressure relief operation has already been performed. At this point, the pressure inside the fuel tank is equal to atmospheric pressure. To verify the specific fault type of the FTIV valve, the vehicle's current operating condition needs to be adjusted to a high-load condition, so that the impact of the FTIV valve's opening and closing on the fuel tank pressure is more pronounced. Under high-load conditions, positive pressure is generated when the engine is running, and the pressure in the fuel system is higher than atmospheric pressure. In this case, the pressure inside the fuel tank is also affected by this positive pressure. Under high-load conditions, the pressure inside the fuel tank is already higher than atmospheric pressure. If the FTIV valve is controlled to open while it is actually open, the fuel tank pressure will significantly decrease during the canister regeneration operation. Therefore, if the pressure change after this canister regeneration operation is greater than or equal to the second threshold, the FTIV valve does not have a stuck-closed fault. If the FTIV valve is actually closed, the positive pressure in the fuel tank cannot be released, and the pressure does not change, or the change is less than the second threshold, indicating a stuck-closed fault in the FTIV valve. Therefore, before determining the second pressure change in the fuel tank by opening the fuel tank isolation valve and performing the carbon canister regeneration operation, the vehicle's current operating condition is adjusted to a high-load condition, ensuring that the fuel tank pressure level is relatively high, that is, sufficiently away from atmospheric pressure. This allows accurate detection of the fuel tank pressure change after the FTIV valve properly opens. Conversely, if the FTIV valve is stuck or normally closed, the detected fuel tank pressure change will be less than the second threshold. This pressure change can then be used to identify whether the FTIV valve is faulty, ensuring fuel tank reliability and environmental performance. Furthermore, the high-load condition is more consistent with the engine operating conditions of hybrid vehicles, thus meeting the diagnostic requirements of hybrid vehicles.

[0072] Furthermore, before determining the third fuel tank pressure change value by closing the fuel tank isolation valve and performing the canister regeneration operation, the canister regeneration operation has already been performed. At this time, the pressure inside the fuel tank is equal to atmospheric pressure. To verify the specific fault type of the FTIV valve, the vehicle's current operating condition needs to be adjusted to a high-load condition, thereby making the impact of the FTIV valve's opening and closing on the fuel tank pressure more pronounced. Under high-load conditions, positive pressure is generated when the engine is running, and the pressure in the fuel system is higher than atmospheric pressure. In this case, the pressure inside the fuel tank is also affected by this positive pressure. Under high-load conditions, the pressure inside the fuel tank is already higher than atmospheric pressure. If the FTIV valve is controlled to be closed while it is actually open, the fuel tank pressure will significantly decrease during the canister regeneration operation. Therefore, if the pressure change value after this canister regeneration operation is greater than the third threshold, it indicates that the FTIV valve has a stuck-open fault. If the FTIV valve is actually closed, the positive pressure in the fuel tank cannot be released, and the pressure does not change, or the pressure change value is less than or equal to the third threshold, indicating that the FTIV valve does not have a stuck-open fault. Therefore, before determining the third fuel tank pressure change value by opening the fuel tank isolation valve and performing the carbon canister regeneration operation, the vehicle's current operating condition is adjusted to a high-load condition, where the fuel tank pressure level is relatively high, sufficiently away from atmospheric pressure. This prevents the FTIV valve from properly closing, preventing any changes in the fuel tank pressure. Conversely, if the FTIV valve is stuck open, the fuel tank pressure change can be accurately detected, allowing the FTIV valve to be identified based on this pressure change, ensuring fuel tank reliability and environmental performance. Furthermore, the high-load condition better aligns with the engine operating conditions of hybrid vehicles, thus meeting the diagnostic requirements of hybrid vehicles.

[0073] Optionally, in another exemplary embodiment, before performing the carbon canister regeneration operation, the method further includes: adjusting the vehicle's current operating condition to a low-load condition. It will be appreciated that when the vehicle's current operating condition is adjusted to a low-load condition, a negative pressure environment is created when the engine is running. This negative pressure can reduce the gas pressure within the carbon canister to a certain level. Therefore, during the carbon canister regeneration operation, a higher vacuum level results in lower gas pressure within the carbon canister, facilitating more efficient desorption of adsorbed substances. In other words, a higher vacuum level results in better desorption, as lower pressure facilitates the release of desorbed gas from the activated carbon surface.

[0074] In this embodiment of the present application, the vehicle's current load condition can be flexibly adjusted based on actual needs before each canister regeneration operation. For example, under high-load conditions, canister regeneration or fuel tank pressure relief can more accurately monitor changes in fuel tank pressure, enabling effective diagnosis of FTIV valve failures. Under low-load conditions, this canister regeneration process can be better assisted, ensuring that fuel vapor in the canister is fully released and effectively absorbed by the engine, thereby improving canister regeneration effectiveness and fuel economy.

[0075] In an exemplary embodiment, the preset conditions include: (1) The pressure of the fuel tank is greater than a fourth threshold.

[0076] It is understandable that if the fuel tank pressure level is at a relatively high level before pressure relief, that is, sufficiently away from the atmospheric pressure level, then after the FTIV valve opens, the change in fuel tank pressure can be accurately captured, which can improve the accuracy of FTIV valve fault diagnosis.

[0077] (2) No refueling request signal is detected.

[0078] It's understandable that when the control system detects a refueling request signal, it opens the FTIV valve to relieve pressure until the tank pressure drops to a safe level, allowing the fuel cap to be opened for refueling. Therefore, before diagnosing the FTIV valve based on the first pressure change value, it's necessary to ensure that no refueling request signal has been received. This ensures that the tank pressure remains at a high level, allowing the subsequent pressure relief operation during fault diagnosis to accurately capture changes in the tank pressure, thereby improving the accuracy of FTIV valve fault diagnosis.

[0079] (3) The temperature of the fuel tank is greater than the fifth threshold and less than the sixth threshold.

[0080] In other words, the fuel tank temperature must be within a reasonable range. If the fuel tank temperature is outside this range, pressure relief may fail, meaning the first pressure change value cannot be accurately determined. In other words, if the temperature is too high, the vapor pressure within the fuel tank may rise prematurely, causing the FTIV valve to automatically open prematurely, leading to unnecessary pressure release. Therefore, by controlling the fuel tank temperature, this unnecessary pressure release can be avoided, ensuring diagnostic accuracy during the current process.

[0081] (4) The pressure sensor of the fuel tank is in a fault-free state.

[0082] That is to say, only when the pressure sensor of the fuel tank is in a normal state, ie, in a fault-free state, can the pressure change of the fuel tank be accurately monitored, so that the accuracy of the obtained first pressure change value is high.

[0083] In this embodiment, in order to ensure that the pressure relief operation is carried out normally, the above (1)-(4) need to be satisfied. In this way, when the pressure relief operation is carried out normally, the determined first pressure change value will be more accurate, thereby improving the accuracy of FTIV valve fault diagnosis.

[0084] In an exemplary embodiment, the preset condition further includes at least one of the following: (5) The vacuum degree of carbon canister desorption is greater than the seventh threshold.

[0085] The vacuum level during carbon canister desorption refers to the degree to which the gas pressure inside the carbon canister decreases during the desorption process, and is usually expressed as the degree of vacuum. During the carbon canister desorption process, the higher the vacuum level, the lower the gas pressure inside the carbon canister, which helps to desorb adsorbed substances more efficiently. In other words, the higher the vacuum level, the better the desorption effect, because the lower pressure helps the desorbed gas to be released more easily from the activated carbon surface.

[0086] (6) The carbon canister flushing flow integral is greater than the eighth threshold.

[0087] The canister flushing flow integral reflects the amount of fuel vapor desorbed from the canister. When the canister flushing flow integral exceeds the eighth threshold, it indicates that most or all of the adsorbed fuel vapor in the canister has been flushed and introduced into the engine for combustion. The canister has been regenerated and has regained its ability to adsorb fuel vapor, ensuring a smooth decompression process.

[0088] (7) The fuel level in the fuel tank is less than or equal to a ninth threshold value and the fuel level signal is valid.

[0089] It is understandable that performing pressure relief operations when the oil level is low can reduce the risk of fuel splashing.

[0090] (8) The engine shutdown time is greater than the tenth threshold.

[0091] It is understandable that when the engine is running, the temperature in the fuel system and engine compartment is high. If a pressure relief operation or other fuel tank-related operations are performed, the high temperature may cause the fuel vapor to expand rapidly, increase the pressure in the fuel tank, and even cause fuel vapor to spray out. However, after standing still, the fuel tank temperature will gradually decrease, which can reduce the occurrence of this risk.

[0092] (9) The current vehicle speed is less than the eleventh threshold.

[0093] It is understandable that when the vehicle is traveling at a low speed, the heat generated by the engine is relatively small, the temperature change in the fuel tank is relatively stable, and the gas pressure in the fuel tank is also relatively stable. In this case, the pressure relief operation will be able to proceed smoothly.

[0094] (10) The difference between the starting water temperature of the engine and the ambient temperature is less than a twelfth threshold.

[0095] The engine's starting water temperature refers to the temperature of the coolant in the cooling system when the engine is started. When the ambient temperature is low, the starting water temperature is also low. When the ambient temperature is high, the starting water temperature is also generally high. Therefore, a large difference between the starting water temperature and the ambient temperature indicates a possible engine malfunction. To ensure proper FTIV valve fault diagnosis, ensure that the engine is not faulty.

[0096] (11) The load of the carbon canister is less than the thirteenth threshold.

[0097] It is understandable that when the fuel tank needs to be depressurized, if the carbon canister is already loaded very high, that is, a large amount of fuel vapor is already stored in the carbon canister, then additional depressurization may cause the carbon canister to be overloaded. Long-term overload operation will cause the activated carbon particles in the carbon canister to become saturated and unable to continue to effectively adsorb vapor, thus causing the carbon canister to become clogged. At the same time, if the carbon canister is already in a high-load state before depressurization, a large amount of fuel vapor will suddenly rush into the carbon canister during depressurization, which may also cause physical damage to the carbon canister and shorten its service life. Therefore, it is necessary to ensure that the load on the carbon canister is at a low level.

[0098] In this embodiment, in order to ensure the accuracy of the diagnosis result, diagnosis can be performed on the basis of satisfying the previous embodiment (1)-(4) and further satisfying at least one of the above (5)-(11).

[0099] Figure 8 Another flow chart of a method for diagnosing a fault of an FTIV valve provided in an embodiment of the present application is shown, which may include the following steps: S805: Determine whether the current vehicle status meets the preset conditions.

[0100] The preset conditions include: the fuel tank pressure is greater than a fourth threshold; no refueling command is detected; the fuel tank temperature is greater than a fifth threshold and less than a sixth threshold; and the fuel tank pressure sensor is in a normal state. Furthermore, the preset conditions may also include: the carbon canister desorption vacuum is greater than a seventh threshold; the carbon canister flushing flow integral is greater than an eighth threshold; the fuel level in the fuel tank is less than or equal to a ninth threshold and the fuel level signal is valid; the engine shutdown duration is greater than a tenth threshold; the current vehicle speed is less than an eleventh threshold; the difference between the engine starting water temperature and the ambient temperature is less than a twelfth threshold; and the carbon canister load is less than a thirteenth threshold.

[0101] S810: The FTIV valve normally open and normally closed diagnosis starts, and the FTIV valve is actively triggered to open for pressure relief.

[0102] It is understandable that after the above conditions are met, the FTIV valve normally open and normally closed diagnosis can be started, that is, the FTIV valve is actively opened to release pressure.

[0103] S815: Determine a change in the first pressure value of the fuel tank before and after the pressure relief.

[0104] S820: Determine whether the change in the first pressure value is greater than a first threshold.

[0105] If the change in the first pressure value is greater than the first threshold, go to S825; if the change in the first pressure value is less than or equal to the first threshold, go to S830.

[0106] S825: The FTIV valve normally open and normally closed diagnosis is completed, and it is determined that the FTIV valve has no faults.

[0107] That is, if the calculated change in the tank pressure measurement value before and after the pressure relief, ie, the change in the first pressure value, exceeds the first threshold, it is determined that the FTIV valve does not have a normally open or normally closed fault.

[0108] S830: When the FTIV valve is opened and the carbon canister is flushed for a certain period of time, a change in a second pressure value of the fuel tank is obtained.

[0109] If the calculated change in the fuel tank pressure measurement value before and after the pressure relief, that is, the change in the first pressure value, is less than a first threshold, it is recognized that the fuel tank is in a non-rapid pressure relief condition, the FTIV valve is opened, and the carbon canister is flushed for a certain period of time. S835: Determine whether the change in the second pressure value is less than a second threshold.

[0110] If the change in the second pressure value is less than the second threshold, go to S840 ; if the change in the second pressure value is less than or equal to the second threshold, go to S845 .

[0111] S840: It is determined that a stuck normally closed fault exists.

[0112] That is, if the change in the front and rear fuel tank pressures, that is, the change in the second pressure value, is less than the second threshold, it is determined that a stuck FTIV valve normally closed fault exists.

[0113] S845: When the FTIV valve is closed and the carbon canister is actively desorbed for a certain period of time, a third pressure value change of the fuel tank is obtained.

[0114] That is to say, the FTIV valve is closed, and the carbon canister solenoid valve is actively opened under high load conditions to desorb the carbon canister for a certain period of time, and the change in the front and rear tank pressures, that is, the change in the third pressure value, is determined.

[0115] S850: Determine whether the change in the third pressure value is greater than a third threshold.

[0116] If the change in the third pressure value is greater than the third threshold, go to S855; if the change in the third pressure value is greater than or equal to the third threshold, go to S860.

[0117] S855: It is determined that there is a stuck normally open fault.

[0118] S860: Determine that the FTIV valve has no faults.

[0119] In this embodiment, by identifying the change in fuel tank pressure before and after the FTIV valve is opened, it is possible to quickly identify whether the FTIV valve has a fault, thereby shortening the diagnosis time. At the same time, by performing carbon canister flushing and carbon canister purge under high load conditions and monitoring the change in fuel tank pressure, the specific fault type of the FTIV valve can be accurately identified. In addition, high load is more consistent with the engine operating conditions of hybrid vehicles, which can improve the diagnosis rate.

[0120] Figure 9 FIG. 1 shows a schematic diagram of a fault diagnosis device for an FTIV valve tank isolation valve provided in an embodiment of the present specification. Figure 9 As shown, the fault diagnosis device 900 for the fuel tank isolation valve may include: a determination module 910 and a diagnosis module 920 .

[0121] In this embodiment, the determination module 910 is used to determine the second pressure change value of the fuel tank in response to the first pressure change value of the fuel tank being less than the first threshold value by opening the fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes carbon canister flushing or carbon canister desorption; the diagnosis module 920 is used to perform fault diagnosis on the fuel tank isolation valve according to the second pressure change value.

[0122] In an exemplary embodiment, the diagnostic module 920 is specifically configured to: in response to the second pressure change value being less than a second threshold, determine that the tank isolation valve has a stuck normally closed fault.

[0123] In an exemplary embodiment, the diagnostic module 920 is specifically used to: in response to the second pressure change value being less than a second threshold value, and the second pressure change value being the pressure change value corresponding to the oil tank from the first moment to the second moment, obtain a first pressure value and a second pressure value, wherein the first pressure value is the pressure value corresponding to the oil tank at the second moment, the second pressure value is the pressure value corresponding to the oil tank at a third moment, the third moment is greater than the second moment, and the second moment is greater than the first moment; in response to the second pressure value being greater than the first pressure value, determine that the oil tank isolation valve has a stuck normally closed fault.

[0124] In an exemplary embodiment, the diagnostic module 920 is specifically configured to: determine a third pressure change value of the fuel tank by closing the fuel tank isolation valve and performing a carbon canister regeneration operation in response to the second pressure change value being greater than or equal to a second threshold; and perform a fault diagnosis on the fuel tank isolation valve based on the third pressure change value.

[0125] In an exemplary embodiment, the diagnostic module 920 is specifically configured to: in response to the third pressure change value being greater than a third threshold, determine that the fuel tank isolation valve has a stuck-open fault.

[0126] In an exemplary embodiment, the diagnostic module 920 is specifically used to: in response to the third pressure change value being greater than a third threshold value, and the third pressure change value being the pressure change value corresponding to the oil tank at a third moment, obtain a third pressure value and a fourth pressure value, wherein the third pressure value is the pressure value corresponding to the oil tank at the third moment, and the fourth pressure value is the pressure value corresponding to the oil tank at the fourth moment; in response to the fourth pressure value being greater than the third pressure value, determine that the oil tank isolation valve has a stuck normally open fault.

[0127] In an exemplary embodiment, the system further includes an adjustment module configured to adjust the current operating condition of the vehicle to a light load operating condition or a heavy load operating condition before determining the first pressure change value by performing the fuel tank pressure relief operation.

[0128] In an exemplary embodiment, the adjustment module is further configured to adjust the current operating condition of the vehicle to a high-load operating condition before performing the carbon canister regeneration operation.

[0129] In an exemplary embodiment, the preset conditions include: the pressure of the fuel tank is greater than a fourth threshold; no refueling command is detected; the temperature of the fuel tank is greater than a fifth threshold and less than a sixth threshold; and the pressure sensor of the fuel tank is in a non-faulty state.

[0130] In an exemplary embodiment, the preset conditions also include at least one of the following: the vacuum degree of carbon canister desorption is greater than the seventh threshold; the carbon canister flushing flow integral is greater than the eighth threshold; the fuel liquid in the fuel tank is less than or equal to the ninth threshold and the fuel level signal is valid; the engine shutdown time is greater than the tenth threshold; the current vehicle speed is less than the eleventh threshold; the difference between the starting water temperature of the engine and the ambient temperature is less than the twelfth threshold; the load of the carbon canister is less than the thirteenth threshold.

[0131] The fault diagnosis device of the fuel tank isolation valve provided in the embodiment of the present application can realize Figure 1 To avoid repetition, the various processes implemented in the illustrated method embodiment will not be described again here.

[0132] The fault diagnosis device for a fuel tank isolation valve in the embodiment of the present application may be a device, or a component, integrated circuit, or chip in an electronic device, which is not specifically limited in the embodiment of the present application.

[0133] In an embodiment of the present application, a fault diagnosis device for a fuel tank isolation valve may be a device having an operating system. The operating system may be an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiment of the present application.

[0134] Optional, such as Figure 10 As shown, an embodiment of the present application further provides an electronic device 1000, including a processor 1010, a memory 1020, and a program or instruction stored in the memory 1020 and executable on the processor 1010. When the program or instruction is executed by the processor 1010, each process of the above-mentioned embodiment of the fault diagnosis method for the oil tank isolation valve is implemented, and the same technical effect can be achieved. To avoid repetition, it will not be described here.

[0135] An embodiment of the present application also provides a computer-readable storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the various processes of the above-mentioned fuel tank isolation valve fault diagnosis method embodiment are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0136] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer-readable storage medium, such as a computer read-only memory (ROM), random access memory (RAM), a magnetic disk, or an optical disk.

[0137] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned fuel tank isolation valve fault diagnosis method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0138] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0139] An embodiment of the present application also provides a computer program product, which includes at least one computer program. When the computer program is loaded and executed by a processor, it implements the various processes of the above-mentioned fuel tank isolation valve fault diagnosis method embodiment and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0140] Figure 11 It is a structural schematic diagram of a vehicle provided in an embodiment of the present application.

[0141] Exemplarily, as shown in FIG11 , the vehicle includes: a memory 1101 and a processor 1102 , wherein the memory 1101 stores an executable program code 11011 , and the processor 1102 is configured to call and execute the executable program code 11011 to implement various processes of the embodiment of the above-mentioned fault diagnosis method for the fuel tank isolation valve.

[0142] This embodiment can divide the vehicle into functional modules based on the above-described method example. For example, each functional module can be mapped to a specific function, or two or more functions can be integrated into a single processing module. The integrated module can be implemented in hardware. It should be noted that the module division in this embodiment is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used.

[0143] In the case of dividing each functional module into corresponding functional modules, the vehicle may include: a determination module, a diagnosis module, etc. It should be noted that all relevant contents of each step involved in the above method embodiment can be referred to the functional description of the corresponding functional module and will not be repeated here.

[0144] The vehicle provided in this embodiment is used to execute the above-mentioned method for diagnosing a fault of a fuel tank isolation valve, and thus can achieve the same effect as the above-mentioned implementation method.

[0145] In the case of an integrated unit, the vehicle may include a processing module and a storage module. The processing module may be used to control and manage the vehicle's movements, while the storage module may be used to support the vehicle's execution of program codes and data.

[0146] The processing module may be a processor or controller that implements or executes the various exemplary logic blocks, modules, and circuits disclosed herein. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processing (DSP) and a microprocessor, and the storage module may be a memory.

[0147] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0148] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0149] Through the description of the above embodiments, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a more preferred embodiment. Based on this understanding, the technical solution of this application, or the part that contributes to the existing technology, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of this application.

[0150] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

Claims

1. A method for diagnosing a fault of a fuel tank isolation valve, characterized in that: The method comprises: In response to a first pressure change value of the fuel tank being less than a first threshold, determining a second pressure change value of the fuel tank by opening a fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes a carbon canister flushing or a carbon canister purge. A fault diagnosis is performed on the fuel tank isolation valve according to the second pressure change value.

2. The method according to claim 1, characterized in that The performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value includes: In response to the second pressure change value being less than a second threshold, it is determined that a stuck normally closed fault exists in the fuel tank isolation valve.

3. The method according to claim 1, characterized in that The performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value includes: In response to the second pressure change value being less than a second threshold value, and the second pressure change value being a pressure change value of the fuel tank from a first moment to a second moment, obtaining a first pressure value and a second pressure value, wherein the first pressure value is a pressure value of the fuel tank at the second moment, and the second pressure value is a pressure value of the fuel tank at a third moment, the third moment being greater than the second moment, and the second moment being greater than the first moment; In response to the second pressure value being greater than the first pressure value, it is determined that a stuck-closed fault exists in the fuel tank isolation valve.

4. The method according to claim 1, wherein The performing fault diagnosis on the fuel tank isolation valve according to the second pressure change value includes: In response to the second pressure change value being greater than or equal to a second threshold, determining a third pressure change value of the fuel tank by closing the fuel tank isolation valve and performing the carbon canister regeneration operation; A fault diagnosis is performed on the fuel tank isolation valve according to the third pressure change value.

5. The method according to claim 4, characterized in that The performing fault diagnosis on the fuel tank isolation valve according to the third pressure change value includes: In response to the third pressure change value being greater than a third threshold, it is determined that a stuck-open fault exists in the fuel tank isolation valve.

6. The method according to claim 4, characterized in that The performing fault diagnosis on the fuel tank isolation valve according to the third pressure change value includes: In response to the third pressure change value being greater than a third threshold value, and the third pressure change value being a pressure change value of the fuel tank corresponding to a fourth moment to a fifth moment, obtaining a third pressure value and a fourth pressure value, wherein the third pressure value is a pressure value of the fuel tank corresponding to the fifth moment, and the fourth pressure value is a pressure value of the fuel tank corresponding to a sixth moment, the sixth moment being greater than the fifth moment, and the fifth moment being greater than the fourth moment; In response to the fourth pressure value being greater than the third pressure value, it is determined that a stuck-open fault exists in the fuel tank isolation valve.

7. The method according to claim 1, characterized in that Before determining the first pressure change value by performing the fuel tank pressure relief operation, the method further includes: adjusting a current operating condition of the vehicle to a light load operating condition or a heavy load operating condition.

8. The method according to claim 1 or 4, characterized in that Before performing the carbon canister regeneration operation, the method further includes: Adjust the vehicle's current operating condition to a high-load condition.

9. The method according to any one of claims 1 to 8, characterized in that The preset conditions include: The pressure of the fuel tank is greater than a fourth threshold; No refueling request signal is detected; The temperature of the fuel tank is greater than a fifth threshold and less than a sixth threshold; The pressure sensor of the fuel tank is in a fault-free state.

10. The method according to claim 9, characterized in that The preset conditions also include at least one of the following: The vacuum degree of carbon canister desorption is greater than the seventh threshold; The carbon canister flushing flow integral is greater than the eighth threshold; The fuel level in the fuel tank is less than or equal to a ninth threshold and the fuel level signal is valid; The engine shutdown time is greater than the tenth threshold; The current vehicle speed is less than the eleventh threshold; The difference between the starting water temperature of the engine and the ambient temperature is less than a twelfth threshold; The load of the carbon canister is less than a thirteenth threshold.

11. A fault diagnosis device for a fuel tank isolation valve, characterized in that: include: a determination module configured to determine, in response to a first pressure change value of the fuel tank being less than a first threshold, a second pressure change value of the fuel tank by opening a fuel tank isolation valve and performing a carbon canister regeneration operation, wherein the first pressure change value is determined by performing a fuel tank pressure relief operation under preset conditions, and the carbon canister regeneration operation includes a carbon canister flushing or a carbon canister purge; A diagnostic module is used to perform fault diagnosis on the fuel tank isolation valve according to the second pressure change value.

12. An electronic device, characterized in that: The method comprises a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the method for diagnosing a fault of an oil tank isolation valve according to any one of claims 1 to 10.

13. A vehicle, characterized in that: The vehicle includes: a memory and a processor, wherein the memory stores executable program code, and the processor is used to call and execute the executable program code. When the executable program code is executed by the processor, the steps of the fault diagnosis method of the fuel tank isolation valve according to any one of claims 1 to 10 are implemented.

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