Camshaft Position Sensor: Description and Operation

CAMSHAFT POSITION (CMP) SENSOR

The camshaft position (CMP) sensor is triggered by a notched reluctor wheel built onto the exhaust camshaft sprocket. The CMP sensor provides four signal pulses every camshaft revolution. Each notch, or feature of the reluctor wheel is of a different size which is used to identify the compression stroke of each cylinder and to enable sequential fuel injection. The CMP sensor is connected to the engine control module (ECM) by the following circuits:
- A 5-Volt reference circuit
- A low reference circuit
- A signal circuit