Crankshaft Position Sensor: Description and Operation

CRANKSHAFT POSITION (CKP) SENSOR
The crankshaft position (CKP) sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets the resulting change in the magnetic field is used by the sensor electronics to produce a digital output pulse. This system uses two sensors within the same housing for the V6 engine, and two separate sensors for the V8 engine. The PCM supplies each sensor a 12-volt reference, low reference, and a signal circuit. The signal circuit returns a digital ON/OFF pulse 24 times per crankshaft revolution.

CRANKSHAFT RELUCTOR WHEEL
The crankshaft reluctor wheel is part of the crankshaft. The notches on the reluctor wheel provide a unique pattern for each pair of cylinders that are at top dead center (TDC) at the same time. This is known as pulse width encoding. This pulse width encoded pattern allows the PCM to quickly recognize which pair of cylinders are at TDC.