Camshaft Position Sensor: Description and Operation

Camshaft Position Sensor Wiring Diagram:

Purpose:
The camshaft position sensor sends a signal to the ECM which uses it as a "sync pulse" to trigger the injectors in proper sequence. The cam signal is not processed but passes through the ignition control module.

Operation:
The camshaft position sensor is a "Hall effect" switch, located on the front top of the engine. It is supplied ignition voltage and has its own ground. The sensor sends a signal to the ECM when the #1 cylinder is on the intake stroke.

This signal is used by the ECM to synchronize Sequential Fuel Injection (SFI) mode of operation with the intake valve opening. If the camshaft position sensor signal is not received by the ECM, the ECM will still operate in SFI mode based on the reference signal, however, SFI mode timing may not be as accurate because the ECM does not know the exact time the intake valve is opening. A slightly rough idle would result.

Location:
The camshaft position sensor is located on the timing cover behind the water pump near the camshaft sprocket.