Crankshaft Position Sensor
4.7L - The Crankshaft Position (CKP) sensor is mounted to right rear side of engine block. See Fig 1 . Engine speed and crankshaft position are provided through the 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. On the 4.7L V-8 engine, a tonewheel is bolted to the engine crankshaft. See Fig 2 . This tonewheel has sets of notches at its outer edge. See Fig 2 . The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.
3.9 & 5.9L - The CKP sensor is mounted on the outer edge of the flywheel (starter ring gear). Engine speed and crankshaft position are provided through the CKP sensor. The sensor generates pulses that are the input sent to the 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.
On 3.9L V-6 engines there are three sets of double notches and three sets of single notches. See Fig 3 . The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM. The engine will not operate if the PCM does not receive a CKP sensor input.
On 5.9L V-8 engines, the flywheel/drive plate has 8 single notches, spaced every 45 degrees, at its outer edge. See Fig 4 . The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM. For each engine revolution there are 8 pulses generated on V-8 engines. The engine will not operate if the PCM does not receive a CKP sensor input.