Crankshaft Sensor

Crankshaft sensor contains a pick-up coil and is located at front of crankshaft, near crankshaft pulley. A signal plate (rotor) is mounted on crankshaft pulley. As crankshaft rotates, protrusions on signal plate pass near pick-up coil. This induces AC voltage in pick-up coil. ECM senses this voltage signal and uses it to determine engine speed and crankshaft position.

The ECM may use input signals for determining ignition timing (spark advance) and for controlling fuel injection system, idle speed control system, heated oxygen sensor system and intake air control valve system.