Crankshaft Position Sensor

The crankshaft position (CKP) sensor senses the protrusion of the signal plate installed to the drive plate to identify fluctuation of the engine revolution.

The sensor consists of a permanent magnet and Hall IC.

When the engine is running, the high and low parts of the teeth cause the gap with the sensor to change.

The changing gap causes the magnetic field near the sensor to change.

Due to the changing magnetic field, the voltage from the sensor changes.

The ECM receives the voltage signal and detects the fluctuation of the engine revolution.

Fig 1: Identifying Crankshaft Position Sensor

Courtesy of NISSAN NORTH AMERICA, INC.

ECM receives the signals as shown in the figure.

Fig 2: Crankshaft Position Sensor Signals Timing Pattern

Courtesy of NISSAN NORTH AMERICA, INC.