Circuit Description

Crankshaft Position (CKP) sensor works in conjunction with a 58-tooth reluctor wheel on crankshaft. ECM pulls CKP sensor signal circuit low and monitors voltage on circuit. As each reluctor wheel tooth rotates past sensor, sensor's internal circuitry causes voltage to be applied to signal circuit, creating a square wave signal used by ECM. Reluctor wheel teeth are 6 degrees apart. Having only 58 teeth leaves a 12-degree span that is uncut. This creates a signature pattern that enables ECM to determine crankshaft position.

ECM can determine which 2 cylinders are approaching top dead center based on CKP signal alone. Camshaft Position (CMP) sensor signal is used to determine which 2 cylinders are on firing stroke. ECM can then properly synchronize ignition system, fuel injectors and knock control. This sensor is also used to detect misfire. Refer to DTC P0300 for misfire detection.

Conditions for setting DTC:

• Reluctor wheel gap is out of range.
• More than 58 teeth were counted before signature tooth.