Cutlass Ciera L4-2.2L VIN 4 (1995)
Crankshaft Position Sensor: Description and Operation
Crankshaft Position Sensor
PURPOSE
This system uses a magnetic Crankshaft Position (CKP) sensor, mounted remotely from the Ignition Control Module (ICM), which protrudes into
the block within approximately 0.050 in. from the crankshaft reluctor. The image shows a typical sensor in relationship to the crankshaft reluctor.
The reluctor is a special wheel cast into the crankshaft with seven slots machined in it, six of which are equally spaced 60 degrees apart. A seventh
slot is spaced 10 degrees from one of the other slots and serves to generate a "sync-pulse." As the reluctor rotates as part of the crankshaft, the
slots change the magnetic field of the sensor, creating an induced voltage pulse. The signal is necessary for the PCM to determine when to
energize the fuel injectors.
OPERATION
Based on the CKP sensor pulses, the CKP sensor sends 7X reference signals to the Powertrain Control Module (PCM) which is used to indicate
crankshaft position and engine speed. The CKP sensor continues to send these reference pulses to the PCM at a rate of seven times per 360
degrees of crankshaft rotation. This signal is called the 7X reference because it occurs 7 times per crankshaft revolution.
