What are the symptoms of a faulty crankshaft position sensor?

Crankshaft position sensor failure impact

If the crankshaft position sensor is damaged, the engine control unit cannot receive the reference signal during startup, and the ignition coil will not generate high voltage. After 2 seconds of turning on the ignition switch, if the engine does not start, the engine control unit will cut off the control voltage to the fuel pump relay, stopping power supply to the fuel pump and ignition coil, resulting in the vehicle being unable to start.

Crankshaft position sensor failure and solutions

1. Magnetic induction type

Advantages: Simple structure, sturdy and durable, high temperature resistance, low assembly requirements.

Disadvantages: Signals are easily interfered with; ECU needs to design related signal processing circuits; lower accuracy; not suitable for engines with WT.

The fault of magnetic induction crankshaft position sensors is that the engine cannot start. When checking the engine condition, it is found that late ignition is the real reason for the engine's inability to start.

Solution: Reconnect the wiring properly and readjust the distributor while checking ignition timing.

2. Hall effect type

Advantages: Outputs a digital signal with high accuracy. Disadvantages: High assembly requirements; sensitive to rotation installation; integrates electrical components with EMC requirements.

The Hall effect crankshaft position sensor controls sequential fuel injection, ignition timing, and knock control for the engine. When a fault occurs, it means that the transmitted signal is not within normal range.

Solution: Check if permanent magnets, magnetic plates, and integrated circuits are functioning normally.

3. Photoelectric type

The fault of photoelectric crankshaft sensors is poor acceleration of the engine; it may stall automatically during startup and sometimes produce high-voltage sparks. The cause is poor operation of the ignition system leading to weak high-voltage sparks.

Solution: Check low-voltage circuits, main relays, internal short circuits in high-voltage ignition coils, faults in engine control units, and abnormal wear of some mechanical components.