Methods to prevent false engine fault codes
By distinguishing the sensor reading value under special operating conditions and the sensor reading value under fault conditions in the fault diagnosis system of the electronically controlled engine, the problem of false alarm code of the engine under special operating conditions is solved, and effective protection of the engine and economic losses are achieved.
Patent Information
- Application Number
- CN202411613717.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-13
- Publication Date
- 2025-04-04
AI Technical Summary
In the prior art, the fault diagnosis system of the electronically controlled engine is prone to falsely report the fault code under special operating conditions, resulting in unnecessary economic losses to the driver and the service station.
By distinguishing the sensor reading value under special operating conditions and the sensor reading value under fault conditions in the fault judgment process, the fault judgment process, the fault state processing process and the non-fault state processing process are adopted to avoid false alarms of fault codes under special operating conditions and torsion-limiting protection of the engine when necessary.
It effectively prevents the engine from falsely reporting fault codes under special operating conditions, avoids economic losses from drivers and service stations, and ensures engine protection.
Smart Images
Figure CN119758947A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of fault diagnosis and control of electronically controlled engines, and in particular to a method for preventing an engine from falsely reporting a fault code. Background Art
[0002] The electronically controlled engine has its own fault diagnosis system. When the engine is abnormal, it will perform automatic diagnosis and report the diagnosis results in the form of fault codes. For some faults, when the fault diagnosis system reports the fault code, the engine controller ECM will also limit the engine torque to protect the engine. At the same time, the fault code will be displayed on the terminal device (such as the instrument panel) in the form of text and indicator lights to remind the driver to go to the service station for inspection and repair.
[0003] The defects of the prior art are:
[0004] 1. In the prior art, some fault codes are reported not because the engine parts are actually faulty, but because some special working conditions (such as instantaneous heavy load) cause the readings of some sensors to exceed the reasonable range in a short period of time, thereby causing the ECM to misjudge, report fault codes and limit torque, and the driver will go to the service station for inspection based on this.
[0005] 2. Due to the false alarm fault code existing in the prior art, it will cause operating losses to the driver on the one hand, and on the other hand, it will mislead the service station to replace parts without solving the problem, further causing economic losses to the driver. Summary of the invention
[0006] In view of the above problems, the present invention provides a method for preventing the engine from falsely reporting fault codes, the purpose of which is to distinguish the sensor readings under special working conditions from the sensor readings under fault conditions, to avoid false reporting of fault codes under special working conditions and causing losses to the driver, and to limit the engine torque in time when necessary to protect the engine.
[0007] To solve the above problems, the technical solution provided by the present invention is:
[0008] The method for preventing the engine from falsely reporting a fault code is characterized by comprising a fault judgment process, a fault state processing process, and a non-fault state processing process, wherein:
[0009] The fault judgment process is used to judge whether the component or system monitored by the sensor is in a fault state;
[0010] The fault state processing flow is used to process the fault code and engine control state under the fault state;
[0011] The non-fault state processing flow is used to process the fault code and the engine control state in the non-fault state.
[0012] Preferably, the fault judgment process specifically includes the following steps:
[0013] Sa100. Determine the components or systems that are prone to false alarm fault codes based on whether the false alarm rate of the fault code exceeds the manually set false alarm rate, and then determine the sensors that monitor the components or systems;
[0014] Sa200. Read the sensor reading of the sensor determined in step Sa100;
[0015] Sa300. Compare the sensor reading with the manually preset diagnostic threshold interval, and then perform the following operations according to the comparison result:
[0016] If the sensor reading exceeds the diagnostic threshold range, the fault state processing flow is executed; if the sensor reading is within the diagnostic threshold range, the non-fault state processing flow is executed.
[0017] Preferably, the fault status processing flow specifically includes the following steps:
[0018] Sb100. The fault timer starts timing and reads the fault timer reading; the start timing of the fault timer is 0;
[0019] Sb200. Compare the current fault timer reading with the manually preset torque limit setting time, and then perform the following operations according to the comparison result:
[0020] If the current fault timer reading is greater than or equal to the torque limit setting time, execute step Sb400;
[0021] If the current fault timer reading is less than the torque limit setting time, step Sb300 is executed; Sb300. The fuel injection amount is kept at a normal value, and the engine is kept in the original state;
[0022] Sb400. The engine running state changes to torque limit state, and the ECM controls the combustion system to reduce the fuel injection amount;
[0023] Sb500. Compare the current fault timer reading with the manually preset fault code setting time, and then perform the following operations according to the comparison result:
[0024] If the current fault timer reading is greater than or equal to the fault code setting time, execute step Sb600;
[0025] If the current fault timer reading is less than the fault code setting time, execute step Sb700;
[0026] Sb600. Determine that the component or system causing the current abnormal sensor reading is faulty, the fault timer reading no longer increases, and the fault timer reading is set to the fault code setting time; then send the fault code information to the ECM diagnostic port;
[0027] Sb700. The fault code information is not reported, and the fault timer continues to count.
[0028] Preferably, the non-fault state processing flow specifically includes the following steps:
[0029] Sc100. The fault timer reading is reset to zero, and the engine exits the torque limit state, and the ECM controls the combustion system to resume normal fuel injection;
[0030] Sc200. The clearing timer of the fault code starts timing and reads the clearing timer reading;
[0031] Sc300. Compare the current clearing timer reading with the manually preset fault code clearing time, and then perform the following operations according to the comparison result:
[0032] If the current clearing timer reading is greater than or equal to the fault code clearing time, execute step Sc400;
[0033] If the current clearing timer reading is less than the fault code clearing time, execute step Sc500;
[0034] Sc400. The clear timer reading is no longer increased, and the clear timer reading is set to the fault code clearing time, and the fault code is cleared at the same time;
[0035] Sc500. Continue to maintain the fault code and the clear timer continues to count.
[0036] Preferably, the method for setting the diagnostic threshold interval is:
[0037] The upper limit and lower limit of the reading value interval of the target attribute of the engine component or system under normal working condition detected by the sensor are respectively set as the upper limit and lower limit of the diagnosis threshold interval.
[0038] Preferably, the target attributes include temperature, pressure, rotation speed, and concentration.
[0039] Preferably, the method for determining the torque limit setting time in step Sb200 is: when the sensor reading exceeds the diagnostic threshold range, the engine is kept in its original state, the fuel injection amount is kept at a normal value, and the longest time without causing damage to the engine and its accessories is set as the torque limit setting time.
[0040] Preferably, the method for taking the value of the fault code setting time in step Sb500 is: setting the longest duration of the abnormal state of the sensor reading of the engine under special working conditions as the fault code setting time.
[0041] Preferably, the special operating condition includes an operating condition where the engine experiences a large load that momentarily exceeds the design capacity of components or systems.
[0042] Preferably, the fault code setting time is greater than the torque limit setting time.
[0043] Compared with the prior art, the present invention has the following advantages:
[0044] 1. Since the present invention can distinguish between sensor readings under special working conditions and sensor readings under fault conditions, it can prevent the engine fault diagnosis system from falsely reporting fault codes under special engine working conditions.
[0045] 2. Since the present invention can prevent the engine fault diagnosis system from falsely reporting fault codes under special engine operating conditions, and can limit the engine torque when necessary, it can protect the engine and prevent the driver from suffering unnecessary economic losses. BRIEF DESCRIPTION OF THE DRAWINGS
[0046] Figure 1 A schematic diagram of a fault judgment process of a specific embodiment of the present invention;
[0047] Figure 2 A schematic diagram of a fault state processing flow of a specific embodiment of the present invention;
[0048] Figure 3 It is a schematic diagram of a non-fault state processing flow of a specific embodiment of the present invention. DETAILED DESCRIPTION
[0049] The present invention is further explained below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application.
[0050] The method for preventing the engine from falsely reporting a fault code is characterized by comprising a fault judgment process, a fault state processing process, and a non-fault state processing process, wherein:
[0051] The fault judgment process is used to determine whether the component or system monitored by the sensor is in a fault state.
[0052] The fault status processing flow is used to process fault codes and engine control status under fault conditions.
[0053] The non-fault state processing flow is used to process fault codes and engine control states in non-fault states.
[0054] It should be noted that if Figure 1 As shown in the figure, the fault judgment process specifically includes the following steps:
[0055] Sa100. Determine the components or systems that are prone to false alarm fault codes based on whether the false alarm rate of the fault code exceeds the manually set false alarm rate, and then determine the sensors that monitor the components or systems. For example, a fault code FC_A indicates that the pressure of a certain intake system FIS is low. After inspection by the after-sales service system, the false alarm rate of the fault code exceeds the set false alarm rate, i.e., 20%. Therefore, it is determined that the pressure sensor FIP of the intake system is the application object of the present invention.
[0056] Sa200. Read the sensor reading value of the sensor determined in step Sa100.
[0057] Sa300 compares the sensor reading with the manually preset diagnostic threshold range, and then performs the following operations based on the comparison results:
[0058] If the sensor reading exceeds the diagnostic threshold range, the fault state processing flow is executed; if the sensor reading is within the diagnostic threshold range, the non-fault state processing flow is executed.
[0059] It should be further explained that the method for determining the sensor is: based on the statistical data of after-sales service, screen out the components or systems whose fault code false alarm rate exceeds the manually set false alarm rate, determine the components or systems that are prone to false alarm fault codes, and then determine the sensors for monitoring the components or systems.
[0060] It should be further explained that the method for setting the diagnostic threshold interval is:
[0061] The upper limit and lower limit of the reading value interval of the target attribute of the engine component or system under normal working condition detected by the sensor are respectively set as the upper limit and lower limit of the diagnosis threshold interval.
[0062] It should be further explained that the target attributes include temperature, pressure, rotation speed, and concentration.
[0063] For example, according to the design of the engine, the normal pressure range of the intake system FIS is 400-1100 kPa. If it is lower than 400 kPa, it is low pressure, and if it is higher than 1100 kPa, it is high pressure. 400 kPa is the diagnostic threshold of the low intake pressure fault code FC_A.
[0064] It should be noted that if Figure 2 As shown in the figure, the fault status processing flow specifically includes the following steps:
[0065] Sb100. The fault timer starts timing and reads the fault timer value; the start timing time of the fault timer is 0.
[0066] Sb200 compares the current fault timer reading with the manually preset torque limit setting time, and then performs the following operations according to the comparison result:
[0067] If the current fault timer reading is greater than or equal to the torque limit setting time, step Sb400 is executed.
[0068] If the current fault timer reading is less than the torque limit setting time, step Sb300 is executed.
[0069] Sb300. The fuel injection amount remains at a normal value and the engine remains in its original state.
[0070] Sb400. The engine operating state changes to torque-limited state, and the ECM controls the combustion system to reduce the amount of fuel injection.
[0071] Sb500. Compares the current fault timer reading with the manually preset fault code setting time, and then performs the following operations based on the comparison result:
[0072] If the current fault timer reading is greater than or equal to the fault code setting time, execute step Sb600.
[0073] If the current fault timer reading is less than the fault code setting time, execute step Sb700.
[0074] Sb600. Determine that the component or system that causes the current sensor reading to be abnormal is faulty, the fault timer reading no longer increases, and the fault timer reading is set to the fault code setting time; then send the fault code information to the ECM diagnostic port.
[0075] Sb700. No fault code information is reported and the fault timer continues to count.
[0076] It should be further explained that in step Sb600, the fault timer reading no longer increases, and the fault timer reading is set to the fault code setting time, the purpose of which is to prevent the fault timer reading from exceeding its maximum value and reporting an overflow fault.
[0077] It should be further explained that the method for determining the torque limit setting time in step Sb200 is: when the sensor reading exceeds the diagnostic threshold range, the engine is kept in its original state, the fuel injection amount is kept at a normal value, and the longest time without causing damage to the engine and its accessories is set as the torque limit setting time.
[0078] For example, if the pressure of the intake pressure system FIS is lower than 400kPa for more than 1 second, it may cause damage to the after-treatment system, so the torque limit setting time is set to 1 second.
[0079] It should be further explained that the method for determining the fault code setting time in step Sb500 is: the longest time that the abnormal state of the sensor reading of the engine under special working conditions lasts is set as the fault code setting time, and at this time the engine has no component or system failure.
[0080] It should be further explained that special operating conditions include those when the engine is subjected to a large load that momentarily exceeds the design capacity of components or systems.
[0081] For example, when the vehicle is fully loaded, climbing a slope, or at full throttle, the intake volume demand of the intake system FIS may exceed the design capacity of the pressure regulating valve, causing the intake pressure FIP to be lower than the diagnostic threshold of 400kPa. According to test data analysis, this condition usually does not exceed 20 seconds, so 20 seconds is set as the fault code setting time.
[0082] It should be further explained that the fault code setting time is greater than the torque limit setting time.
[0083] It should be further explained that the fault diagnosis system will only report the fault code when the fault timer reading in step Sb500 is greater than or equal to the fault code setting time; this can filter out abnormal sensor readings under special working conditions, thereby avoiding false fault code reports under special working conditions.
[0084] It should be further explained that the values of the fault code setting time and the torque limit setting time are set based on experimental results.
[0085] It should be noted that if Figure 3 As shown, the non-fault state processing flow specifically includes the following steps:
[0086] Sc100. The fault timer reading is cleared to zero, and the engine exits the torque limit state, and the ECM controls the combustion system to resume normal fuel injection.
[0087] Sc200. The clearing timer of the fault code starts timing and the clearing timer reading value is read.
[0088] Sc300. Compare the current clear timer reading with the manually preset fault code clear time, and then perform the following operations based on the comparison result:
[0089] If the current clearing timer reading is greater than or equal to the fault code clearing time, execute step Sc400.
[0090] If the current clearing timer reading is less than the fault code clearing time, execute step Sc500.
[0091] Sc400. The clear timer reading no longer increases, and the clear timer reading is set to the fault code clearing time, and the fault code is cleared at the same time.
[0092] Sc500. Continue to maintain the fault code and clear the timer to continue timing.
[0093] It should be further explained that the clear timer reading no longer increases, and the clear timer reading is set as the fault code clearing time, the purpose of which is to prevent the clear timer reading from exceeding its maximum value and reporting an overflow fault.
[0094] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.
[0095] The disclosed embodiments are described above to enable any person skilled in the art to implement or use the present invention. Various modifications of these embodiments are obvious to those skilled in the art, and the general principles defined herein may also be applied to other embodiments without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.
[0096] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," is explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".
[0097] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for preventing an engine from falsely reporting a fault code, characterized in that: It includes fault judgment process, fault status processing process, and non-fault status processing process, among which: The fault judgment process is used to judge whether the component or system monitored by the sensor is in a fault state; The fault status processing flow is used to process the fault code and engine control status under the fault status; The non-fault state processing flow is used to process the fault code and the engine control state in the non-fault state.
2. The method for preventing an engine from falsely reporting a fault code according to claim 1, characterized in that: The fault judgment process specifically includes the following steps: Sa100. Determine the components or systems that are prone to false alarm fault codes based on whether the false alarm rate of the fault code exceeds the manually set false alarm rate, and then determine the sensors that monitor the components or systems; Sa200. Read the sensor reading of the sensor determined in step Sa100; Sa300. Compare the sensor reading with the manually preset diagnostic threshold interval, and then perform the following operations according to the comparison result: If the sensor reading exceeds the diagnostic threshold range, the fault state processing flow is executed; if the sensor reading is within the diagnostic threshold range, the non-fault state processing flow is executed.
3. The method for preventing an engine from falsely reporting a fault code according to claim 2, characterized in that: The fault status processing flow specifically includes the following steps: Sb100. The fault timer starts timing and reads the fault timer reading; the start timing of the fault timer is 0; Sb200. Compare the current fault timer reading with the manually preset torque limit setting time, and then perform the following operations according to the comparison result: If the current fault timer reading is greater than or equal to the torque limit setting time, execute step Sb400; If the current fault timer reading is less than the torque limit setting time, execute step Sb300; Sb300. The fuel injection amount remains at a normal value and the engine remains in its original state; Sb400. The engine running state changes to torque limit state, and the ECM controls the combustion system to reduce the fuel injection amount; Sb500. Compare the current fault timer reading with the manually preset fault code setting time, and then perform the following operations according to the comparison result: If the current fault timer reading is greater than or equal to the fault code setting time, execute step Sb600; If the current fault timer reading is less than the fault code setting time, execute step Sb700; Sb600. Determine that the component or system causing the current abnormal sensor reading is faulty, the fault timer reading no longer increases, and the fault timer reading is set to the fault code setting time; Then send the fault code information to the ECM diagnostic port; Sb700. The fault code information is not reported, and the fault timer continues to count.
4. The method for preventing an engine from falsely reporting a fault code according to claim 3, characterized in that: The non-fault state processing flow specifically includes the following steps: Sc100. The fault timer reading is reset to zero, and the engine exits the torque limit state, and the ECM controls the combustion system to resume normal fuel injection; Sc200. The clearing timer of the fault code starts timing and reads the clearing timer reading; Sc300. Compare the current clearing timer reading with the manually preset fault code clearing time, and then perform the following operations according to the comparison result: If the current clearing timer reading is greater than or equal to the fault code clearing time, execute step Sc400; If the current clearing timer reading is less than the fault code clearing time, execute step Sc500; Sc400. The clear timer reading is no longer increased, and the clear timer reading is set to the fault code clearing time, and the fault code is cleared at the same time; Sc500. Continue to maintain the fault code and the clear timer continues to count.
5. The method for preventing an engine from falsely reporting a fault code according to claim 2, characterized in that: The method for setting the diagnostic threshold interval is: The upper limit and lower limit of the reading value interval of the target attribute of the engine component or system under normal working condition detected by the sensor are respectively set as the upper limit and lower limit of the diagnosis threshold interval.
6. The method for preventing an engine from falsely reporting a fault code according to claim 5, characterized in that: The target attributes include temperature, pressure, rotation speed, and concentration.
7. The method for preventing an engine from falsely reporting a fault code according to claim 3, characterized in that: The method for determining the value of the torque limit setting time in step Sb200 is: when the sensor reading exceeds the diagnostic threshold range, the longest time for maintaining the engine in its original state and the fuel injection amount at a normal value without causing damage to the engine and its accessories is set as the torque limit setting time.
8. The method for preventing an engine from falsely reporting a fault code according to claim 3, characterized in that: The method for obtaining the value of the fault code setting time in step Sb500 is: setting the longest duration of the abnormal state of the sensor reading of the engine under special working conditions as the fault code setting time.
9. The method for preventing an engine from falsely reporting a fault code according to claim 8, characterized in that: The special operating conditions include the conditions when the engine is subjected to a large load that exceeds the design capacity of components or systems for an instant.
10. The method for preventing an engine from falsely reporting a fault code according to claim 9, characterized in that: The fault code setting time is greater than the torque limit setting time.