Camshaft Position (CMP) Sensor
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2009 Mercury Mountaineer, 2009 Mercury Milan, 2009 Mercury Mariner, 2009 Mercury Grand Marquis, and 2009 Lincoln Town Car. 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 number 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 correct ignition coil to fire.
Vehicles with two CMP sensors are equipped with variable camshaft timing (VCT). The second sensor is used to identify the position of the camshaft on bank 2.
There are two types of CMP sensors: the 2-pin variable reluctance type sensor and the 3-pin Hall-effect type sensor.