Crankshaft Position Sensor: Description and Operation

The Crankshaft Position (CKP) sensor is located near the outer edge of the flywheel (starter ring gear).

Engine speed and crankshaft position are provided through the CKP sensor. The sensor generates pulses that are the input sent to the Powertrain Control Module (PCM). The PCM interprets the sensor input to determine the crankshaft position. The PCM then uses this position, along with other inputs, to determine injector sequence and ignition timing.

The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.

Fig.24 CKP Sensor Operation - 5.9L Engine:

On this, the flywheel/drive plate has 8 single notches, spaced every 45 degrees, at its outer edge.

The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM. For each engine revolution, there are 8 pulses generated on V-8 engines.

The engine will not operate if the PCM does not receive a CKP sensor input.