Camshaft Position Sensor: Description and Operation

PURPOSE
The signal from the camshaft position sensor combined with the input signal from the Crankshaft Position (CKP) Sensor, are what the Powertrain Control Module (PCM) uses to differentiate between fuel and spark events. Input is also used to properly synchronize fuel injection.

OPERATION
The Powertrain Control Module (PCM) and identifies cylinders by monitoring signals from the crankshaft and camshaft position sensors. The PCM uses these input signals to determine fuel injector synchronization. The ICM uses these input signals to determine which ignition coil to fire.

The camshaft position sensor generates a high/low voltage signal, as slots in the camshaft gear are detected. When a slot passes in front of the sensor, a 5 volt signal is sent to the PCM. When a slot is not present, the PCM receives a 0.3 volt signal.

If PCM does not sense input from cam position sensor, PCM will deactivate ASD and fuel pump relay, interrupting voltage to fuel pump, fuel injectors, and ignition coil, causing a no start condition.