Cylinder Identification Sensor: Description and Operation

Distributor:

PURPOSE
The Camshaft Position (CMP) sensor detects cylinder #1 TDC compression stroke. The Powertrain Control Module (PCM) uses this signal to calculate fuel injection timing.

OPERATION
The sensor uses a disc with 1 slot which rotates with the distributor shaft. As the disc rotates, the slot passes through a fixed photo sensor, indicating cylinder #1 TDC compression to the PCM.