Method for diagnosing engine misfire caused by wire harness and vehicle

Abstract

The invention discloses a method for diagnosing engine misfire caused by a wire harness and a vehicle. The method comprises the steps that it is confirmed that an engine shakes abnormally; an ECU fault code is read through a diagnostic instrument; the misfire type is determined according to the ECU fault code, and the misfire type comprises single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation; and finding out a corresponding troubleshooting scheme according to the corresponding fire type, and carrying out troubleshooting through the corresponding troubleshooting scheme. The misfire types of the engine are divided into single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation. And the diagnostic instrument is used for reading the ECU fault code, and the misfire type of the engine is determined through the ECU fault code. And a corresponding troubleshooting scheme is found for the corresponding fire type, and the target vehicle is rapidly troubleshot through the corresponding troubleshooting scheme. The efficiency of vehicle troubleshooting is improved, and the vehicle is convenient to check and maintain. The invention is mainly used in the technical field of vehicles.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a diagnostic method for engine misfire caused by a wire harness and a vehicle. BACKGROUND

[0002] In the current vehicle technology, all are driven and controlled by engines in the form of fuel energy. During the operation of the engine, the problem of engine misfire and cylinder loss may occur, which is fundamentally caused by the failure of the mixed gas in the cylinder to burn normally or completely. However, for the vehicle wire harness profession, there is a lack of clear steps for troubleshooting and troubleshooting schemes for wire harness problems when assisting in troubleshooting engine misfire, resulting in low troubleshooting efficiency and difficulty in covering all possible causes during the troubleshooting process, making it difficult to solve the problem. Therefore, how to efficiently troubleshoot engine misfire through the wire harness direction is a technical problem that needs to be studied in the industry. SUMMARY

[0003] The present application provides a diagnostic method for engine misfire caused by a wire harness and a vehicle to help maintenance personnel efficiently troubleshoot engine misfire through the wire harness direction, and at least provides a beneficial choice or creates conditions.

[0004] The present application provides a diagnostic method for engine misfire caused by a wire harness, comprising: confirming that the engine is abnormally shaking; reading the ECU fault code through a diagnostic instrument; determining the misfire type according to the ECU fault code, wherein the misfire type includes single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation; finding the corresponding troubleshooting scheme according to the corresponding misfire type, and troubleshooting through the corresponding troubleshooting scheme.

[0005] Further, when the misfire type is single-cylinder misfire, the corresponding troubleshooting scheme includes: interchanging the ignition coil and spark plug of the fault cylinder with the ignition coil and spark plug of the non-fault cylinder, and if the problem still does not disappear after interchanging, then troubleshooting the injector and the corresponding wire harness of the ignition coil.

[0006] Further, when the misfire type is single-cylinder misfire, the corresponding troubleshooting scheme further includes: troubleshooting the plug-in connector of the injector and the corresponding wire harness of the ignition coil.

[0007] Further, when the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme includes: connecting the vehicle battery, turning on the ignition switch, checking whether the voltage of the power pin in the ignition coil plug-in connector is 12V, and checking whether the upstream relay and fuse are ablated and fused.

[0008] Further, when the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme further includes: simulating driving shaking by gently shaking the connection between the wire harness and the plug-in connector, and observing whether the corresponding state is reproduced.

[0009] Further, when the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme further comprises: checking whether the rust or looseness exists in the ignition coil ironing point and the engine ECU ironing point.

[0010] Further, when the misfire type is fuel correction value deviation, the corresponding troubleshooting scheme comprises: troubleshooting the crankshaft position sensor wire harness, the camshaft position sensor wire harness, the throttle position sensor wire harness and the intake pressure sensor wire harness to find out the fault point.

[0011] Further, when the misfire type is fuel correction value deviation, the corresponding troubleshooting scheme further comprises: troubleshooting the plug-in parts of the crankshaft position sensor wire harness, the camshaft position sensor wire harness, the throttle position sensor wire harness and the intake pressure sensor wire harness.

[0012] Further, the judgment standard of the fuel correction value deviation is that the fuel correction value deviation is greater than 80%.

[0013] On the other hand, a vehicle is provided, which is processed by the wire harness caused engine misfire diagnosis method according to any one of the above technical solutions.

[0014] The method of the present application has at least the following beneficial effects: the method of the present application divides the misfire type of the engine into single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation. And the diagnostic instrument is used to read the ECU fault code, and the misfire type of the engine is determined through the ECU fault code. And the corresponding troubleshooting scheme is found for the corresponding misfire type, and the target vehicle is quickly checked through the corresponding troubleshooting scheme. The efficiency of vehicle fault troubleshooting is improved, and the vehicle is convenient for checking and repairing. At the same time, the present application also provides a corresponding vehicle, and the beneficial effects of the vehicle are similar to those of the method, which will not be described here. The present application is mainly used in the technical field of vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0016] Figure 1 is a step flow chart of the wire harness caused engine misfire diagnosis method; Figure 2 is a structural schematic diagram of the wire harness caused engine misfire diagnosis device; Figure 3 is a hardware structure of the wire harness caused engine misfire diagnosis device of another embodiment. DETAILED DESCRIPTION

[0017] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0018] It should be noted that although the functional modules are divided in the system schematic diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in a manner different from the module division in the system or the order in the flowchart. The terms "first", "second", etc. in the specification and claims and the above drawings are used to distinguish similar objects, and do not necessarily describe a specific order or sequence.

[0019] Before the embodiments of the present application are described in detail, first, some nouns and terms involved in the embodiments of the present application will be explained, and the nouns and terms involved in the embodiments of the present application are applicable to the following explanations.

[0020] ECU fault code, when the ECU monitors that the working parameter of a sensor, actuator or circuit exceeds the preset normal range, it will record this event as a fault code.

[0021] In the related art of vehicles, how to help maintenance personnel efficiently troubleshoot the engine misfire through the wire harness direction and improve the maintenance efficiency is a technical problem urgently needed to be researched in the industry.

[0022] Please refer to Figure 1 , Figure 1 is a step flowchart of the diagnosis method of the wire harness causing engine misfire.

[0023] The present application discloses a diagnosis method of a wire harness causing engine misfire, and the steps specifically implemented by the diagnosis method of the wire harness causing engine misfire include: step 1, confirming that the engine has abnormal vibration.

[0024] When the engine of the target vehicle has the problem of misfire and lack of cylinder, the most intuitive performance is that the engine has abnormal vibration. Therefore, when it is found that the engine has abnormal vibration, it can be considered that the engine has the problem of misfire and lack of cylinder. At this time, the confirmation of the problem of engine misfire and lack of cylinder can be made by retrieving the corresponding ECU fault code.

[0025] Step 2, reading the ECU fault code through the diagnostic instrument.

[0026] The diagnostic instrument can be connected to the target vehicle to read the ECU fault code of the target vehicle. Of course, in some further embodiments, in addition to reading the ECU fault code of the target vehicle, the engine misfire and lack of cylinder problem of the target vehicle can be confirmed by reading the corresponding waveform diagram.

[0027] Step 3, determining the misfire type according to the ECU fault code, wherein the misfire type includes single cylinder misfire, multi-cylinder misfire and fuel correction value deviation.

[0028] After obtaining the ECU fault code through the diagnostic instrument, the ECU fault code can be analyzed to determine the misfire type of the engine of the target vehicle. The misfire type includes single cylinder misfire, multi-cylinder misfire and fuel correction value deviation.

[0029] Through research, it is found that the wire harnesses that can be affected by these misfire types include engine ignition coil wire harness and connector, engine fuel injector wire harness and connector, crankshaft position sensor / camshaft position sensor wire harness and connector, throttle position sensor / intake pressure sensor wire harness and connector, common power supply wire harness / ground wire harness and connector.

[0030] For the engine ignition coil wire harness and connector, the main reason is that the power supply line or ground wire to the ignition coil is broken, the coil does not work. The control signal line is short-circuited to ground / power supply, the ECU cannot correctly control the ignition, which leads to lack of cylinder. The internal terminals of the ignition coil connector are corroded, loose, and the pins are withdrawn, which causes the contact resistance to be too large, resulting in intermittent misfire (more obvious when the vehicle is vibrating and accelerating). The insulation layer of the wire harness is damaged due to friction with metal parts such as engine cylinder, sheet metal and bracket, resulting in short circuit to ground, causing the fuse to blow and the system to fail.

[0031] For the engine fuel injector wire harness and connector, the main reason is that the fuel injector power supply or control line is broken, the fuel injector does not spray oil at all, and the signal line short circuit will also cause the ECU control to fail. The internal terminals of the fuel injector connector are withdrawn and water enters, etc., which increases the loop resistance, causing the fuel injector to work unstably, the fuel injection amount to be inaccurate or intermittent.

[0032] For the crankshaft position sensor / camshaft position sensor wire harness and connector, the main reason is that the crankshaft position sensor wire harness is disturbed and intermittently broken, which will cause the ECU to be unable to accurately determine the crankshaft position and speed, thereby incorrectly cutting off the ignition or fuel injection, causing random or multi-cylinder misfire.

[0033] For the throttle position sensor / air intake pressure sensor harness and connector, the main reason is that the sensor signal misalignment will affect the ECU calculation of the load and intake volume, resulting in air-fuel ratio imbalance and misfire.

[0034] For the common power supply harness / ground harness and connector, the main reason is that the power supply line in the main relay power supply line has problems, affecting the simultaneous operation of multiple cylinders. The ECU or engine ignition coil ground torque does not meet the standard, is not tightened, is rusted, etc. The loop resistance is too large, affecting the work of all electrical components that share this ground point (such as multiple ignition coils and fuel injectors), causing multiple random misfires.

[0035] Step 4, find the corresponding troubleshooting scheme according to the corresponding misfire type, and troubleshoot according to the corresponding troubleshooting scheme.

[0036] After determining the misfire type, the corresponding troubleshooting scheme can be found. The found troubleshooting scheme can quickly troubleshoot the target vehicle.

[0037] The engine misfire type is divided into single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation. The diagnostic instrument is used to read the ECU fault code, and the ECU fault code is used to determine the engine misfire type. And find the corresponding troubleshooting scheme for the corresponding misfire type, and quickly troubleshoot the target vehicle through the corresponding troubleshooting scheme. Improve the efficiency of vehicle fault troubleshooting, and facilitate vehicle inspection and maintenance.

[0038] After determining that the engine misfire type is single-cylinder misfire, the corresponding troubleshooting scheme can be found. In order to facilitate description, the troubleshooting scheme is referred to as the first troubleshooting scheme. The first troubleshooting scheme includes: interchanging the ignition coil and spark plug of the fault cylinder with the ignition coil and spark plug of the non-fault cylinder, and if the problem still does not disappear after interchanging, troubleshooting the fuel injector and ignition coil corresponding harness. Through the first troubleshooting scheme, the harness condition causing single-cylinder misfire can be quickly locked, and corresponding maintenance can be performed.

[0039] Of course, for the troubleshooting of the harness, in addition to the condition of the harness itself, the connector of the harness also needs to be correspondingly troubleshooted. Therefore, in some further specific embodiments, when the misfire type is single-cylinder misfire, the first troubleshooting scheme further includes: troubleshooting the plug-in connector of the fuel injector and ignition coil corresponding harness.

[0040] For determining the misfire type of the engine as multi-cylinder misfire, a corresponding troubleshooting scheme can be found. For the convenience of description, the troubleshooting scheme is recorded as a second troubleshooting scheme. The second troubleshooting scheme includes connecting the vehicle storage battery, turning on the ignition switch, checking whether the voltage of the power supply pin of the ignition coil plug-in connector to the ground is 12V, and checking whether the upstream relay and fuse are ablated and fused. Through the second troubleshooting scheme, the wire harness condition causing multi-cylinder misfire can be quickly locked, and corresponding maintenance can be performed.

[0041] In some further embodiments, when the misfire type is multi-cylinder misfire, the second troubleshooting scheme further includes: simulating driving shaking by gently shaking the wire harness and plug-in connector connection, and observing whether the corresponding state is reproduced.

[0042] In some further embodiments, when the misfire type is multi-cylinder misfire, the second troubleshooting scheme further includes: checking whether the ignition coil grounding point and the engine ECU grounding point are rusted or loose.

[0043] For determining the misfire type of the engine as fuel correction value deviation, a corresponding troubleshooting scheme can be found. For the convenience of description, the troubleshooting scheme is recorded as a third troubleshooting scheme. The third troubleshooting scheme includes troubleshooting the crankshaft position sensor wire harness, the camshaft position sensor wire harness, the throttle position sensor wire harness, and the intake pressure sensor wire harness to find the fault point. Through the third troubleshooting scheme, the wire harness condition causing fuel correction value deviation can be quickly locked, and corresponding maintenance can be performed.

[0044] Of course, for troubleshooting of the wire harness, in addition to the condition of the wire harness itself, the plug-in connector of the wire harness also needs to be correspondingly troubleshooted. In some further embodiments, when the misfire type is fuel correction value deviation, the third troubleshooting scheme further includes: troubleshooting the plug-in connector of the crankshaft position sensor wire harness, the plug-in connector of the camshaft position sensor wire harness, the plug-in connector of the throttle position sensor wire harness, and the plug-in connector of the intake pressure sensor wire harness.

[0045] The judgment standard for fuel correction value deviation is that the fuel correction value deviation is greater than 80%.

[0046] On the other hand, a vehicle is provided, which is processed by the wire harness causing engine misfire diagnosis method of any one of the above embodiments.

[0047] Of course, in some cases of automatic wire harness detection, the wire harness causing engine misfire diagnosis method can also form a corresponding program and be loaded into the wire harness causing engine misfire diagnosis device, and automatic operation can be performed by the wire harness causing engine misfire diagnosis device.

[0048] ReferenceFigure 2 , Figure 2 is a structural diagram of a wire harness-induced engine misfire diagnosis device.

[0049] In another aspect, there is provided a wire harness-induced engine misfire diagnosis device, comprising: a processor and a memory for storing a computer-readable program. When the computer-readable program is executed by the processor, the processor implements the wire harness-induced engine misfire diagnosis method according to any one of the above embodiments.

[0050] Those of ordinary skill in the art will understand that all or some of the steps in the above disclosed method can be implemented as software, firmware, hardware, or a suitable combination thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application specific integrated circuit. Such software can be distributed on computer readable media, which can include computer storage media (or non-transitory media) and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. As is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term "modulated data signal" means a signal that has one or more of its characteristics changed or set in a manner so as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of the above should also be included within the scope of computer readable media.

[0051] Referring to Figure 3 , Figure 3 is a hardware structure of a wire harness-induced engine misfire diagnosis device of another embodiment. The wire harness-induced engine misfire diagnosis device comprises a processor 901, a memory 902, an input / output interface 903, a communication interface 904, and a bus 905.

[0052] The processor 901 can be implemented by a general-purpose CPU (Central Processing Unit), a microprocessor, an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits, and is configured to execute related programs to implement the harness-caused engine misfire diagnosis method provided by the embodiments of the present application.

[0053] The memory 902 can be implemented by a ROM (Read Only Memory), a static storage device, a dynamic storage device, or a RAM (Random Access Memory), and the like. The memory 902 can store an operating system and other application programs, and when the technical solutions provided by the embodiments of the present application are implemented by software or firmware, the related program codes are stored in the memory 902 and called and executed by the processor 901 to implement the method provided by the embodiments of the present application.

[0054] The input / output interface 903 is configured to implement information input and output.

[0055] The communication interface 904 is configured to implement the communication interaction between the device and other devices, and can realize the communication through a wired manner (for example, a USB, a network cable, and the like) or a wireless manner (for example, a mobile network, WIFI, Bluetooth, and the like).

[0056] The bus 905 is configured to transmit information between various components (for example, the processor 901, the memory 902, the input / output interface 903, and the communication interface 904) of the device.

[0057] The processor 901, the memory 902, the input / output interface 903, and the communication interface 904 are connected to each other through the bus 905 to realize the communication connection between the device.

[0058] In another aspect, a computer readable storage medium is provided, and the computer readable storage medium stores a processor executable program. The processor executable program is executed by a processor to implement the harness-caused engine misfire diagnosis method provided by any one of the above specific embodiments.

[0059] The embodiments of the present application further disclose a computer program product, which comprises a computer program or computer instructions, and the computer program or computer instructions are stored in a computer readable storage medium. A processor of a computer device reads the computer program or computer instructions from the computer readable storage medium, and the processor executes the computer program or computer instructions to enable the computer device to execute the harness-caused engine misfire diagnosis method provided by any one of the above embodiments.

[0060] The terms "first", "second", "third", "fourth" and the like in the description of this application and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the use of the terms so termed is interchangeable under appropriate circumstances such that the embodiments of the application described herein are, for example, capable of accomplishing functionalities that are either the same or similar to that of other embodiments of the application. Moreover, the terms "include", "have", and the like, as well as any variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, system, product, or apparatus that comprises a list of elements is not necessarily limited to those elements but can include other elements not expressly listed or inherent to such process, method, system, product, or apparatus.

[0061] It should be understood that, in the application, "at least one" means one or more, and "multiple" means two or more. "And / or", used to describe the relationship between associated objects, means that there can be three relationships, for example, "A and / or B" can mean: only A, only B, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally represents an "or" relationship between the associated objects. "At least one of the following" or similar expressions means any combination of these items, including any combination of single or multiple items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0062] In several embodiments provided in the application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are only illustrative, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the displayed or discussed each other can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0063] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, i.e. they can be located in one place or distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the application.

[0064] In addition, each of the functional units in each of the embodiments of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0065] When the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0066] Although the description of the present application has been quite detailed and particularly described with respect to several described embodiments, it is not intended to be limited to any of these details or embodiments or any special embodiment, but should be considered to effectively cover the intended scope of the present application by referring to the appended claims, taking into account the broadest possible interpretation of these claims in view of the prior art. In addition, the present application is described above in embodiments that the inventors can foresee, and the purpose is to provide a useful description, and non-essential modifications to the present application that have not yet been foreseen can still represent equivalent modifications to the present application.

[0067] It should be noted that in each of the specific embodiments of the present application, when it is necessary to perform relevant processing according to user information, user behavior data, user history data, and user location information, and other data related to the identity or characteristics of the user, the user's permission or consent will be obtained first, and the collection, use and processing of these data will comply with relevant laws, regulations and standards. In addition, when the embodiments of the present application need to obtain sensitive personal information of the user, the separate permission or separate consent of the user will be obtained through a pop-up window or by jumping to a confirmation page, and after obtaining the separate permission or separate consent of the user, the necessary user-related data for enabling the embodiments of the present application to operate normally will be obtained.

Claims

1. A diagnostic method of wire harness induced engine misfire, characterized by, The method comprises the following steps: Confirming that the engine has abnormal vibration; Reading the ECU fault code through a diagnostic instrument; Determining the misfire type according to the ECU fault code, wherein the misfire type includes single-cylinder misfire, multi-cylinder misfire and fuel correction value deviation; finding a corresponding troubleshooting scheme according to the corresponding misfire type, and troubleshooting through the corresponding troubleshooting scheme.

2. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 1, characterized by, When the misfire type is single-cylinder misfire, the corresponding troubleshooting scheme includes: interchanging the ignition coil and spark plug of the fault cylinder with the ignition coil and spark plug of the non-fault cylinder, and if the problem still does not disappear after interchanging, troubleshooting the injector and the corresponding wire harness of the ignition coil.

3. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 2, characterized by, When the misfire type is single-cylinder misfire, the corresponding troubleshooting scheme further includes: troubleshooting the plug-in parts of the injector and the ignition coil corresponding wire harness.

4. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 1, characterized by, When the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme includes: connecting the vehicle storage battery, turning on the ignition switch, checking whether the voltage of the power supply pin to ground in the ignition coil plug-in part is 12V, and checking whether the upstream relay and fuse are ablated or fused.

5. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 4, characterized by, When the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme further includes: simulating driving vibration by slightly shaking the wire harness and plug-in part connection, and observing whether the corresponding state is reproduced.

6. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 4, characterized by, When the misfire type is multi-cylinder misfire, the corresponding troubleshooting scheme further includes: checking whether the rust or looseness exists in the grounding point of the ignition coil and the grounding point of the engine ECU.

7. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 1, characterized by, When the misfire type is fuel correction value deviation, the corresponding troubleshooting scheme includes: troubleshooting the crankshaft position sensor wire harness, the camshaft position sensor wire harness, the throttle position sensor wire harness and the intake pressure sensor wire harness to find the fault point.

8. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 4, characterized by, When the misfire type is fuel correction value deviation, the corresponding troubleshooting scheme further includes: troubleshooting the plug-in parts of the crankshaft position sensor wire harness, the camshaft position sensor wire harness, the throttle position sensor wire harness and the intake pressure sensor wire harness.

9. The diagnostic method of misfire of an engine caused by a wiring harness according to claim 1, characterized by, The judgment standard of the fuel correction value deviation is that the fuel correction value deviation is greater than 80%.

10. A vehicle characterized by comprising: The vehicle is processed by the wire harness diagnosis method of any one of claims 1 to 9.

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