Camshaft Position Sensor: Description and Operation

CAMSHAFT POSITION (CMP) SENSOR

The CMP sensor signal is a digital ON/OFF pulse, output once per revolution of the camshaft. The CMP sensor does not directly affect the operation of the ignition system. The CMP sensor information is used by the ECM to determine the position of the valve train relative to the crankshaft. By monitoring the CMP and CKP signals the ECM can accurately time the operation of the fuel injectors. The ECM supplies the CMP sensor with a 12-volt reference circuit and a low reference circuit. The CMP sensor signal is an input to the ECM. The CMP is protected from electromagnetic interference by the same shielding circuit used by the CKP sensor.