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Crankshaft Position Sensor (3.7L)

WARNING: This page is about a different car, the 2003 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

The Crankshaft Position (CKP) sensor is mounted into right rear side of cylinder block. See Fig 1 . Engine speed and crankshaft position are provided through the CKP sensor. The sensor generates input pulses that are then 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 tonewheel is bolted to the engine crankshaft. See Fig 2 . This tonewheel has sets of notches at its outer edge. These notches cause a pulse to be generated when they pass under the sensor. Pulses are the input to the PCM.

Fig 1: Locating CKP Sensor (3.7L)
G00079699Courtesy of DAIMLERCHRYSLER CORPORATION
Fig 2: CKP Sensor Operation & Tonewheel (3.7L)
G00094483Courtesy of DAIMLERCHRYSLER CORPORATION