Crankshaft Position Sensor: Description and Operation

CRANKSHAFT POSITION SENSOR (CKPS) (OBD)
The crankshaft position sensor (OBD) is located on the transmission housing facing the gear teeth (cogs) of the flywheel (drive plate). It detects the fluctuation of the engine revolution. The sensor consists of a permanent magnet, core and coil. When engine is running, the gap between the sensor and the gear teeth (cogs) will periodically change. Permeability near the sensor also changes.

Due to the permeability change, the magnetic flux near the core is changed. Therefore, the voltage signal generated in the coil is changed.

The Engine Control Module (ECM) receives the voltage signal and detects the fluctuation of the engine revolution.

This sensor is not directly used to control the engine system. It is used only for the on-board diagnosis of misfire.