Crankshaft Position Sensor (57X Signal)
WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2002 Saturn Vue, 2002 Pontiac Montana, 2002 Pontiac Aztek, 2002 Oldsmobile Silhouette, and 2002 Oldsmobile Bravada. However, it is still accessible from the selected car via links, so may be relevant.
The Crankshaft Position (CKP) sensor is a Hall Effect type sensor mounted at front of crankshaft sprocket. Front crankshaft sprocket has 57 teeth and plus a sync gap. CKP sensor will output and on-off pulse as each window passes the sensing element. CKP sensor is connected directly to PCM by a 12-volt reference circuit, a low reference circuit and a CKP sensor signal circuit. PCM uses CKP sensor signal to determine engine RPM. This signal is used to improve idle. If pump cam signal is lost, PCM will use crankshaft position signal data to control injection timing and fuel flow.