Crankshaft Position Sensor System Diagnosis

Crankshaft Position Sensor System Diagnosis

Circuit Description

The ignition control module (ICM) monitors the crankshaft position (CKP) sensor sync signal when the engine is cranking. The CKP sync signal is passed from the CKP sensor to the ICM on the CKP sensor 2 signal circuit. The CKP sync signal is used to determine the correct cylinder pair and initiate the ignition coil firing sequence. The 18X reference pulses are passed from the CKP sensor to the ICM on the CKP sensor 1 signal circuit. The 18X reference pulses are used for fuel injection and ignition control. After the ICM receives both signals, the ICM passes the 18X and 3X reference signals to the powertrain control module (PCM). The camshaft position sensor and the CKP sensor share a 12-volt reference and a low reference circuit. The CKP sensor consists of the following circuits:

* A 12-volt reference circuit
* A low reference circuit
* A CKP sensor 1 signal circuit
* A CKP sensor 2 signal circuit

Test

Step 1 - Step 13:

Step 14 - Step 26:

Step 27 - Step 31: