Camshaft Position Sensor
A 3-pin Hall Effect type Camshaft Position (CMP) sensor or a 2-pin variable reluctance sensor is used. See Fig 1 and Fig 2 . CMP sensor is used to determine camshaft position and to identify when piston No. 1 is on its compression stroke. CMP sensor signal is used by PCM for synchronizing the firing of sequential fuel injectors. Applications with Coil On Plug (COP) ignition also use CMP signal to select the proper ignition coil to fire. The input circuit to PCM is referred to as the CMP input or circuit.