Camshaft Position Sensor: Description and Operation

CAMSHAFT POSITION (CMP) SENSOR

The CMP sensor is a signal generator that is composed of a magnet and a coil with an iron core. The PCM relies on the AC signal provided by the CMP sensor in order perform the following:
- To optimize the ignition timing
- To optimize the fuel delivery
- To detect any engine misfire

Operation




The camshaft position (CMP) sensor (1) is fastened to the backside of the timing belt cover (2) of the left bank cylinder head. The cam gear (4) is attached to the left bank camshaft (3) inside the timing belt cover (2). The CMP sensor signal rotor is integral to the cam gear (4). The signal rotor has three unevenly spaced teeth. When each tooth of the signal rotor moves past the CMP sensor (1), an electrical signal is generated. These AC signals, three per camshaft revolution, are sent to the PCM.