Crankshaft Position Sensor: Description and Operation

Crankshaft Position Sensor:

PURPOSE
The signal from the Crankshaft Position (CKP) Sensor is used to determine crankshaft angle, engine speed, and basic timing.

Powertrain Control Module (PCM) also uses the signal from the Crankshaft Position (CKP) Sensor combined with the input signal from the camshaft position sensor to properly synchronize injection.

The Ignition Control Module (ICM) uses crankshaft position to determine ignition timing






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 PCM. For each engine revolution there are 5 groups of 2 pulses generated.

Crankshaft position is determined during cranking. Once the last slot of a set has been detected, crankshaft position can be determined by camshaft position input. This process may take up to one complete crankshaft revolution.

If PCM does not sense input from the crankshaft position sensor, PCM will deactivate ASD and fuel pump relay, interrupting voltage to fuel pump, fuel injectors, and ignition coil, (no start condition).

CIRCUIT OPERATION
The Crankshaft Position Sensor is located on the right side center of the engine block.

Circuit K7 supplies 8 volts from the Powertrain Control Module (PCM) to the crankshaft position sensor. The K7 circuit connects to cavity 7 of the PCM.

Circuit K24 from the sensor provides an input signal to the PCM. The K24 circuit connects to cavity 24 of the PCM. The K24 circuit is also an input to the Ignition Control Module (ICM) and connects to cavity 20.

The PCM provides a ground for the crankshaft position sensor signal (circuit K24) through circuit K4. Circuit K4 connects to cavity 4 of the PCM connector.