Sierra 3500 2WD V8-6.0L VIN U (2004)
Crankshaft Position Sensor: Description and Operation
CRANKSHAFT POSITION (CKP) SENSOR
The crankshaft position (CKP) sensor is a three wire sensor based on the magneto resistive principle. A magneto resistive sensor uses two magnetic
pickups between a permanent magnet. As an element such as a reluctor wheel passes the magnets the resulting change in the magnetic field is used by the
sensor electronics to produce a digital output pulse. The PCM supplies a 12-volt, low reference, and signal circuit to the CKP sensor. The sensor returns
a digital ON/OFF pulse 24 times per crankshaft revolution.