Circuit Description

Camshaft Position (CMP) sensor works in conjunction with a single-tooth reluctor wheel on bank 2 intake camshaft. ECM increases CMP sensor signal circuit to 12 volts and monitors this voltage. As reluctor wheel tooth rotates past sensor, sensor's internal circuitry pulls signal circuit to ground, creating a square wave signal used by ECM. Reluctor wheel tooth covers 180 degrees of camshaft circumference.

This causes CMP signal voltage to transition once per crankshaft revolution. This signal, when combined with CKP sensor signal, enables ECM to determine exactly which cylinder is on firing stroke. ECM can then properly synchronize ignition system, fuel injectors and knock control. Note that as long as CKP sensor signal is available, engine can start even if there is no CMP sensor signal. ECM will default to non-sequential fuel injection operation.

Conditions required to set DTC are:

• CMP signal is incorrect for at least 500 milliseconds.
• Engine has completed at least 100 revolutions.