Crankshaft Position Sensor: Description and Operation

SYSTEM OPERATION
Engine speed and crankshaft position are provided through the crankshaft position 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.

Sensor Operation:

The flywheel/drive plate has groups of notches at its outer edge. On this engine, there are three sets of double notches and three sets of single notches.

The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.

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