Today, the customer drove about half an hour in the city. The engine failure indicator and the side slip indicator suddenly turned on. After driving about 10 kilometers, the fault indicator was still on. The customer was annoyed and completely repaired because he had just bought a car for less than 10 days. Customers reported that the car did not have a high-quality installation.

　　故障识别:维修人员根据客户描述对车辆进行检查。1. 当技术人员启动车辆时，发现发动机故障指示灯和侧滑指示灯都亮着，并观察里程表为220KM，确认结果与客户描述相符。2. 使用GTS读取故障代码P0500速度传感器。3.观察车辆。该车辆没有任何精品安装。技术人员初步判断故障原因:1、速度信号电路是开路还是短路。2. 组合仪表总成失效。3.ECM失败。

　　Fault identification: Maintenance personnel inspect the vehicle according to customer description. 1. When the technicians start the vehicle, they find that the engine fault indicator and the side slip indicator are on, and observe the odometer is 220 KM. The results are consistent with the customer description. 2. Use GTS to read the fault code P0500 speed sensor. 3. Observe the vehicle. The vehicle does not have any high-quality installation. Technicians preliminarily determine the causes of the failure: 1. Whether the speed signal circuit is open or short-circuit. 2. Failure of assembled instrument assembly. 3. ECM failed.

　　故障维修:1。故障代码为P0500速度传感器。，查阅维修手册，了解故障代码的情况是:车辆行驶时没有向ECM (First logic)发送速度信号。

　　Troubleshooting: 1. The fault code is P0500 speed sensor. First of all, consult the maintenance manual to understand the fault code: the vehicle does not send speed signals to the ECM (First Logic) when driving.

　　2. 检查电路图，了解速度信号传输过程:ABS传感器→ABS计算机→仪器装配(放大速度信号)→ECM、导航、ECU等。

　　2. Check the circuit diagram to understand the speed signal transmission process: ABS sensor ABS computer instrument assembly ECM, navigation, ECU, etc.

　　当齿轮为D2，发动机转速约为1000 RPM时，车辆将以0 km/h的速度行驶。如果发生故障，ECM数据流中不显示车速。

　　When the gear is D2 and the engine speed is about 1000 RPM, the vehicle will travel at a speed of 0 km/h. If a fault occurs, the ECM data stream does not show the speed.

　　4. 删除故障代码。行驶200米后，故障指示灯将再次亮起。

　　4. Delete the fault code. After driving 200 meters, the fault indicator will be turned on again.

　　5. 配合客户对车辆进行测试，读取ABS系统的数据流。显示四轮速度和车辆速度，表明速度信号可以从速度传感器传输到ABS计算机。同时，ABS系统的速度与测速仪的速度一致，表明速度信号可以从ABS计算机传输到组合仪表。

　　5. Cooperate with customers to test vehicles and read data stream of ABS system. It shows the four-wheel speed and vehicle speed, indicating that the speed signal can be transmitted from the speed sensor to the ABS computer. At the same time, the speed of ABS system is consistent with that of the tachometer, which indicates that the speed signal can be transmitted from the ABS computer to the combined instrument.

　　6. 读取电力系统的数据流，发现无论在何种工况下，车速始终为0 km/h。同时，巡航系统在车速计为60KM/H时运行，巡航系统无法正常设置。开车时打开音响系统，喇叭的声音不会随着车速的变化而改变。

　　6. Read the data flow of the power system and find that the speed of the vehicle is always 0 km/h under any working condition. At the same time, the cruise system can not be set up normally when the speedometer is 60KM/H. Turn on the sound system while driving, and the sound of the horn will not change with the speed of the car.

　　7. 通过以上检测分析，速度信号从速度传感器中断到组合仪表，无法到达ECM。

　　7. Through the above detection and analysis, the speed signal is interrupted from the speed sensor to the combined instrument, and can not reach the ECM.

　　8. 测量组合仪与ECM速度信号线束F2接线端子12与A24接线端子8之间的电阻值小于1欧姆，正常。

　　8. The resistance between the measuring instrument and the terminal 12 of ECM speed signal bundle F2 and terminal 8 of A24 is less than 1 ohm, which is normal.

　　9. 示波器用于测量组合仪表与ECM之间速度信号的波形电压，车辆运行时电压始终为0 v

　　9. The oscilloscope is used to measure the waveform voltage of the speed signal between the combined instrument and ECM. The voltage of the vehicle is always 0 V when it is running.

　　10. 判断组合仪表不能对速度信号进行放大。提供车辆更换仪器的故障排除。三天后，他回到客户那里，说问题已经解决，故障指示灯没有再亮。

　　10. Judging that the combination instrument can not amplify the speed signal. Provide troubleshooting for vehicle replacement instruments. Three days later, he returned to the customer and said that the problem had been solved and the fault indicator had not been turned on again.