Crankshaft Position Sensor: Description and Operation

Dual Crankshaft Sensor:

The crank sensor is mounted in a pedestal on the front of the engine near the harmonic balancer. The sensor is a hall-effect switch which depends on a metal interrupter ring mounted on the balancer to activate it. Windows in the interrupter activate the hall-effect switch as they provide a path for the magnetic field between the switch's transducer, for the magnetic field, between the switch's transducer and it's magnet. When the hall-effect switch is activated, it grounds the signal line to the C3I module, pulling the crank signal applied voltage low, which is interpreted as a crank signal. Because of the way the signal by the crank sensor is created, the signal circuit is always either at a high or low voltage signal, and three signal pulses are created during each crankshaft revolution. This signal is used by the C3I module to create a reference signal which is also a square wave signal similar to the crank signal. The reference signal is used to calculate engine rpm and crankshaft position by the ECM.