Crankshaft Position Sensor: Description and Operation

PURPOSE
The Crankshaft Position Sensor is a signal generator or pickup coil which produces an output pulse to the Engine Control Module (ECM) 4 times per distributor rotation. The ECM uses this signal to determine engine speed and relative TDC for each cylinder.

OPERATION
Whenever the engine is rotating, a sine-wave signal is returned to the ECM. The pulses occurs at camshaft intervals of 90°. As engine speed increases the frequency of the signal increases as well.

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