Crankshaft Position Sensor: Description and Operation

Crankshaft Position (CKP) Sensor 4.0L:

Crankshaft Position (CKP) Sensor Operation:

The Cranckshaft Position Sensor (CPS) is attached to the flywheel/drive plate houosing of the transmission. The CPS is a Hall effect device combined with an internal magnet. The CPS is sensitive to steel within a certain distance from it.

The flywheel/drive plate has groups of 4 notches at its edge. There are three sets of slots.

The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the engine controller. For each engine revolution there are 3 groups of four pulses. The engine controller determines engine speed and crankshaft position based on the pulses.

The trailing edge of the fourth notch (which causes the pulse) is four degrees before top dead center (TDC) of the corresponding Piston.

The engine will not operate if the engine controller does not recieve a CPS input.