Crankshaft Position Sensor

The crankshaft position sensor detects slots cut into a disk in the middle of the crankshaft. See Fig 1 .

Fig 1: Identifying Crankshaft Timing Slots

Courtesy of CHRYSLER CORP.

There are a 5 sets of slots. Each set contains 2 slots, for a total of 10 slots. Basic timing is determined by the position of the last slot in each group. Once the Powertrain Control Module (PCM) and Ignition Control Module (ICM) senses the last slot, they determine crankshaft position, which piston will next be at TDC, from the camshaft position sensor input. It may take the modules up to one engine revolution to determine crankshaft position during cranking. The PCM uses the camshaft reference sensor to determine injector sequence. Once crankshaft. position has been determined, the PCM begins energizing the injectors in sequence. The PCM determines ignition timing from the crankshaft timing sensor. The crankshaft position sensor is located in the passengers side of the engine block, below the exhaust manifold. See Fig 2 .

Fig 2: Locating Crankshaft Position Sensor

Courtesy of CHRYSLER CORP.