Maintenance Recruitment: Maintenance and Maintenance of Vehicle Sensors

Vehicle sensors are now widely used. It is the input device of automobile computer system, which can make all kinds of automobiles in operation.

The working condition information is converted into a telecommunication signal and transmitted to the computer so that the engine is in the best working condition. There are many sensors used in vehicles. When judging the faults of sensors, we should not only consider the sensor itself, but also consider the whole circuit of faults. Therefore, in order to find faults, besides checking sensors, we should also check the wiring harness, connectors and related circuits between sensors and electronic control units. Now let's get to know the main sensors on the car.

Air flow sensor

Air flow sensor converts inhaled air into electrical signal and sends it to electronic control unit, which determines one of the basic signals of fuel injection. According to different measuring principles, it can be divided into rotary vane air flow sensor, hot wire air flow sensor and so on.

Solar term door position sensor

The throttle position sensor is mounted on the throttle to detect the throttle opening. Through the linkage of lever mechanism and throttle, the different working conditions of the engine are reflected. This kind of sensor can input the different working conditions of the engine into the electronic control unit, so as to control the different amount of fuel injection.

Crankshaft Position Sensor

Crankshaft position sensor is the most important sensor in computer controlled ignition system. Its function is to detect upper dead-end signal, crankshaft rotation angle signal and engine speed signal. Different types of crankshaft position sensors have different control modes and precision. The crankshaft position sensor is generally installed on the side of the crankshaft pulley or sprocket, some on the front end of the camshaft, and some on the distributor.

1. Damage of intake pressure temperature sensor:

(1) On gear, engine fault lights are always on;

(2) a small amount of black smoke is emitted when stepping on the accelerator slowly in situ, and a large amount of black smoke is emitted when accelerating rapidly;

(3) engine is not strong;

(4) fault code: P01D6 (intake pressure sensor voltage is below the lower limit) cause analysis: the intake pressure signal is abnormal, and the ECU can not receive the correct intake information, resulting in different fuel injection volume. Often, the combustion is insufficient, the engine is weak, and black smoke is emitted in the process of refueling. Problems with harness connection and sensor failure can lead to the failure. Solution: Check the intake pressure temperature sensor.

2. Damage of water temperature sensor:

(1) ON gear, engine fault lights are always on;

(2) ON gear water temperature always shows the maximum value of 120 C;

(3) engine limit torsion, inertia;

(4) fault code: P003D (water temperature sensor voltage below the lower limit value) cause analysis: water temperature sensor failure, ECU detected that the output signal of water temperature sensor is not credible when using replacement value, ECU for the protection of the engine. Aim To limit engine torque. Solution: Check the water temperature sensor.

3. Damage of oil pressure sensor:

After startup, oil pressure indicator lights are always on; engine fault lights are always on; idle speed, oil pressure value shows 0.99; fault code: P01CA (oil pressure sensor voltage is higher than the upper limit) cause analysis: oil pressure sensor probe is seriously damaged, ECU detects that oil pressure sensor is not connected, instrument display value is within ECU. Partial substitution value. Solution: Check the oil pressure sensor.