Crankshaft Position Sensor: Description and Operation

Typical DIS Crankshaft Sensor:

PURPOSE
The crankshaft sensor provides a signal through the Direct Ignition (DI), which the ECM uses as reference to calculate rpm and crankshaft position.

OPERATION
This sensor protrudes into the block, within approximately .050" of the engine crankshaft reluctor. The reluctor is a special wheel cast into the crankshaft with seven slots cast into it, six of which are evenly spaced 60° apart. A seventh slot is spaced 10° from one of the other slots and serves to generate a "sync pulse." As the reluctor rotates as part of the crankshaft, the slots change the magnetic field of the sensor, creating an induced voltage pulse.

Based on the crank sensor pulses, the ignition module sends reference signals to the ECM which are used to indicate crankshaft position and engine speed.

LOCATION
This sensor is mounted remotely from the ignition module, right hand side of engine, at the end of the crank shaft.