The vehicle sensor is the input device of the vehicle computer system. It converts the information of various working conditions during the operation of the vehicle, such as vehicle speed, temperature of various media, and engine operating conditions, into electrical signals and sends them to the computer, so that the engine is in the best condition. working status. There are many sensors for vehicles. When judging the failure of the sensor, we should not only consider the sensor itself, but the entire circuit that has failed. Therefore, when looking for faults, in addition to checking the sensor, it is also necessary to check the wiring harness, the connector and the related circuit between the sensor and the electronic control unit. One of the characteristics of automotive technology development is that more and more components are electronically controlled. According to the function of the sensor, it can be classified into sensors that measure temperature, pressure, flow rate, position, gas concentration, speed, brightness, dry humidity, distance and other functions. They perform their own duties. Once a sensor fails, the corresponding device will work. It will not work properly or even work. Therefore, the role of the sensor in the car is very important. Automotive sensors used to be purely on the engine and have been extended to the chassis, body and lighting electrical systems. There are more than 100 sensors used in these systems. Among a wide variety of sensors, the common ones are: intake pressure sensor: it reflects the change of absolute pressure in the intake manifold, and provides the ECU (engine electronic control unit) with a reference signal for calculating the duration of injection;