Crankshaft Position Sensor
The Crankshaft Position Sensor (CKP) sensor is a 3-wire sensor based on the magneto resistive principle. A magneto resistive sensor uses 2 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 4 times per crankshaft revolution. The CKP sensor reads the crankshaft mounted reluctor wheel to identify pairs of cylinders at Top Dead Center (TDC). See Fig 1 . If PCM detects that the CKP sensor signal is incorrect, a DTC will set. To diagnose, see SELF-DIAGNOSTICS - 4.3L SIERRA & SILVERADO article.