Sensor Operation

DESCRIPTION
Engine speed and crankshaft position are provided through the crankshaft position sensor. 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. 5 Sensor Operation:

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

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

OPERATION
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 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.