Why is the crankshaft sensor broken? What is the problem with the unstable signal of the crankshaft sensor?

The crankshaft position sensor is one of the most important sensors in the EFI engine control system, and it is also a sensor shared by the ignition system and the fuel injection system. It can determine the position of the crankshaft, detect the piston top dead center signal and the crankshaft angle signal, and send the detected signals to the ECU for controlling the ignition timing and fuel injection timing, and can also detect the engine speed. However, the sensor is a precision instrument, and it is inevitable that there will be problems or damage, so why is the crankshaft sensor broken? Let's get to know it together.

The crankshaft sensor is damaged, which may be caused by improper installation. In addition, the crankshaft position sensor has many forms. Different models have different types of crankshaft position sensors. According to the principle of signal generation by the sensor, they can be divided into three types: magnetic induction, photoelectric and Hall. Different types of sensors, The reasons for the failure are also different:

1. Magnetic induction type

The malfunction of the magneto-inductive crankshaft position sensor is that the engine cannot be started. In this case, reconnect the wiring, re-adjust the distributor, and check the ignition timing.

2. Hall effect

The failure of the Hall-effect crankshaft position sensor is that the transmission signal is not within the normal range. In this case, check whether the permanent magnets, magnetic conductive plates and integrated circuits are normal.

3. Photoelectric

The malfunction of the photoelectric crankshaft sensor is poor engine acceleration, automatic flameout will occur when starting, and sometimes high-voltage electric spark will appear. The reason is that the ignition system is not working properly, causing the high-pressure fire to be weak.In this case, check the low-voltage circuit, the main relay, the internal short circuit of the high-voltage ignition coil, and the engine control unit.YuanThere are malfunctions and abnormal wear of some mechanical parts.

If the crankshaft sensor is damaged, the engine fault light on the car dashboard will light up. The engine computer cannot receive the signal from the crankshaft position sensor, and cannot confirm the crankshaft angle. The car will have no high-voltage electricity, cannot start, and does not ignite or inject fuel. If the signal of the crankshaft sensor is unstable, it may be caused by poor contact or damage to the sensor, which may easily cause misjudgment. Even if the engine can be started, it cannot work stably, and it will be difficult to accelerate, and it needs to be overhauled or replaced in time.