Camshaft Position Sensor

Camshaft Position (CMP) sensor provides ignition reference for cylinder No. 1. When CMP fails, knock control is switched off and since cylinder allocation is no longer possible, ignition angle is slightly retarded. On vehicles equipped with a turbocharger boost pressure is also decreased.

Engine will continue to run and can be restarted without CMP. When malfunction is recognized, Engine Control Module (ECM) initiates one ignition spark per cylinder for each crankshaft rotation. Offset of one engine rotation will have on noticeable effect on fuel injection. Instead of occurring with intake valves open, fuel injection will be "pre-loaded" (fuel is stored in front of closed intake valve). This will only have a minor effect on quality of mixture.