Camshaft Position Sensor

WARNING: This page is about a different car, the 2003 GMC Savana and 2003 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.

The Camshaft Position (CMP) sensor is a hall-effect type sensor. The sensor produces one signal for each revolution of the camshaft in order to control the sequential fuel injection. The CMP sensor is designed to detect changes in a magnetic field. The PCM supplies the CMP sensor with a 12-volt reference circuit, a low reference circuit and a signal circuit. The CMP sensor produces a magnetic field whenever ignition is on. The CMP sensor is mounted near a reluctor wheel that is attached to the distributor shaft. When the distributor shaft rotates, and the reluctor wheel tooth passes by the CMP sensor, there is a change in the magnetic field. The CMP sensor converts each change in the magnetic field into a PULSE. If PCM does not detect the CMP signal while the engine is running, a DTC will set. To diagnose DTC, see SELF-DIAGNOSTICS - 4.3L CHEVY EXPRESS & SAVANA article.