Cherokee 4WD L6-242 4.0L VIN S MFI (1992)
Crankshaft Position Sensor: Description and Operation
Crankshaft Position (CKP) Sensor 4.0L
Crankshaft Position (CKP) Sensor Operation
LOCATION
The sensor is located on the bellhousing of the transmission.
PURPOSE
The signal from the Crankshaft Position Sensor (CPS) is used to determine crankshaft angle, engine speed, and basic timing.
Engine controller also uses the signal from the Crankshaft Position Sensor (CPS) combined with the input signal from the camshaft position sensor
to properly synchronize injection.
OPERATION
The crankshaft position sensor is a hall effect switch that detect notches on a pulse ring mounted to the crankshaft.
The notches cause a pulse to be generated when they pass under the sensor. The pulses are input to the engine controller. For each engine
revolution there are 3 groups of 4 pulses generated.
The trailing edge of the fourth notch is 4 degrees before top dead center of its corresponding cylinder.
If engine controller does not sense input from the crankshaft position sensor, engine controller will deactivate ASD and fuel pump relay,
interrupting voltage to fuel pump, fuel injectors, and ignition coil, (no start condition).
