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Crankshaft Position Sensor: Operation: 3.7L

Engine speed and crankshaft position are provided through the CKP (Crankshaft Position) sensor. The sensor generates pulses that are the input sent to the Powertrain Control Module (PCM). The PCM interprets the sensor input to determine the crankshaft position. The PCM then uses this position, along with other inputs, to determine injector sequence and ignition timing.

The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.

A tone wheel (target wheel) is bolted to the engine crankshaft. This tone wheel has sets of notches at its outer edge.

Fig 1: Identifying CKP Operation - 3.7L
G01741356Courtesy of DAIMLERCHRYSLER CORP.

The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.