Camshaft Position (CMP) Sensor

WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2005 Mercury Sable, 2005 Mercury Mountaineer, 2005 Mercury Monterey, 2005 Mercury Montego, and 2005 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.

The CMP sensor detects the position of the camshaft. The CMP sensor identifies when piston No. 1 is on its compression stroke. A signal is then sent to the PCM and used for synchronizing the sequential firing of the fuel injectors. Coil-on-plug (COP) ignition applications use the CMP signal to select the proper ignition coil to fire. The input circuit to the PCM is referred to as the CMP input or circuit. DTC P0340 is associated with this sensor.

Vehicles with 2 CMP sensors are equipped with variable camshaft timing (VCT). They use the second sensor to identify the position of the camshaft on bank 2 as an input to the PCM. DTC P0345 is associated with this sensor and it is referred to as CMP2.

There are 2 types of CMP sensors: the 3-pin connector Hall-effect type sensor (only used on F-150 4.2L applications) and the 2 pin connector variable reluctance type sensor used on all other vehicle applications.

Fig 1: F-150 4.2L Hall-Effect CMP Sensor

Courtesy of FORD MOTOR CO.

Fig 2: Identifying Camshaft Position (CMP) Sensor

Courtesy of FORD MOTOR CO.