Crankshaft Position Sensor: Description and Operation

The sensor consists of magnet and coil. It is mounted on oil pan with specified air gap between the sensor core end and crankshaft timing belt pulley tooth.

As the crankshaft turns, AC voltage (pulse) is generated in the sensor.

ECM (PCM) uses this signal as;
- a data to calculate the engine speed
- one of the signals for cylinder identification
- one of the signals to monitor occurrence of a misfire

Engine Start Signal
This signal is sent from the engine starter circuit. By receiving it, ECM (PCM) judges whether the engine is cranking or not and uses it as one of the signals to control the fuel injector and fuel pump relay.