Camshaft Position Sensor: Description and Operation

Camshaft Position Sensor - 3.7L:

The Camshaft Position Sensor (CMP) on the 3.7L 6-cylinder engine is bolted to the right-front side of the right cylinder head.

The camshaft position (CMP) sensor is mounted in the top of cylinder head cover/intake manifold at the rear of the engine.The CMP sensor is a hall effect device that detects a notch on the rear of the exhaust camshaft that allows the ECM to determine the position of cylinder number one. The engine will continue to run if the signal is lost, but will not restart after the vehicle is shut off.

Camshaft Position Sensor Location - 3.7L:

The Camshaft Position Sensor (CMP) sensor contains a hall effect device referred to as a sync signal generator. A rotating target wheel (tonewheel) for the CMP is located at the front of the camshaft for the right cylinder head. This sync signal generator detects notches located on a tonewheel. As the tonewheel rotates, the notches pass through the sync signal generator. The signal from the CMP sensor is used in conjunction with the Crankshaft Position Sensor (CKP) to differentiate between fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.

When the leading edge of the tonewheel notch enters the tip of the CMP, the interruption of magnetic field causes the voltage to switch high, resulting in a sync signal of approximately 5 volts.

When the trailing edge of the tonewheel notch leaves then tip of the CMP, the change of the magnetic field causes the sync signal voltage to switch low to 0 volts.