Operation CHARM: Car repair manuals for everyone.

Camshaft Position Sensor: Description and Operation

Fig.4 CMP Location - 4.7L Engine:




The Camshaft Position Sensor (CMP) on the 4.7L V-8 engine is bolted to the front/top of the right cylinder head.

Fig.5 CMP Sensor And Tonewheel - 4.7L Engine:




The CMP sensor contains a hall effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator detects notches located on a tonewheel. The tonewheel is located at the front of the camshaft for the right cylinder head. As the tonewheel rotates, the notches pass through the sync signal generator. The pattern of the notches (viewed counter-clockwise from front of engine) is: 1 notch, 2 notches, 3 notches, 3 notches, 2 notches 1 notch, 3 notches and 1 notch. The signal from the CMP sensor is used in conjunction with the crankshaft position sensor to differentiate between

fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders.