Cylinder Identification Sensor: Description and Operation

PURPOSE
In a Sequential Electronic Fuel Injection (SEFI) system each individual fuel injector is energized just prior to the opening of its corresponding intake valve. The Camshaft Position (CMP) sensor is used to identify when number 1 cylinder is on compression stroke and to generate the Cylinder Identification (CID) signal. This CID signal allows the Powertrain Control Module (PCM) to sequence the fuel injectors in the correct order.

OPERATION
The CMP is a variable reluctance type sensor that senses a single tooth (corresponding to number 1 cylinder compression stroke) on the camshaft. the sensor generates a sinusoidal signal every time the tooth passes by the CMP sensor. The output signal and ground path of the CMP sensor is routed directly to the PCM. Because the CMP is a variable reluctance type sensor, it generates its own voltage and does not require a power supply input.

RELATED DIAGNOSTIC TROUBLE CODES

DTC 214 - Cylinder Identification (CID) circuit failure.