Cylinder Identification Sensor: Description and Operation

PURPOSE
The Camshaft Position Signal provides the Powertrain Control Module (PCM) with a signal that represents No.1 Cylinder @ Top Dead Center (TDC). This signal is used by the PCM for calculating proper ignition system output.


OPERATION

NOTE: The CAMSHAFT POSITION SIGNAL used in the ignition system is not related to the component Camshaft Position Sensor. The component Camshaft Position Sensor is used for fuel injection timing purposes and should not be confused with the ignition system signal "CAMSHAFT POSITION SIGNAL".

- The Ignition Control Module receives the Crankshaft Position Signal from the Crankshaft Position Sensor (CKP).
- The Ignition Control Module converts the CKP signal into a "CAMSHAFT POSITION SIGNAL".
- The PCM uses the CAMSHAFT POSITION SIGNAL to detect when the No.1 Cyl. is at Top Dead Center.
- The PCM uses a programed spark advance map to process the CAMSHAFT POSITION SIGNAL along with other system inputs to produce a Spark Output (SPOUT) signal.
- The Ignition Control Module uses the SPOUT and CKP input signals to control the ignition spark timing by switching the primary circuits of the ignition coils On and Off.

CONSTRUCTION
The Camshaft Position Signal is exactly what its name implies; a signal. The component is a non tangible component SIGNAL which is used as a PCM input. The signal represents when the No.1 Cyl. is @ TDC. Since this TDC event repeats with every engine revolution, the signal coincides with engine speed. The Camshaft Position Signal will produce an RPM signal when probed at the PCM input Pin No.56.