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Crankshaft Position Sensor Operation

The crankshaft position sensor is either mounted on the bottom of the DIS ignition module or next to the ignition module. See Figure, Fig 1 and Figure. The sensor protrudes into the engine block, within 0.05" (1.3 mm) of crankshaft reluctor. Sensor position is not adjustable.

The reluctor is a special wheel cast into the crankshaft with 7 slots machined into it, 6 of which are equally spaced (about 60 degrees apart). A seventh slot is spaced 10 degrees from one of the other slots and serves to generate a synchronization pulse signal. As reluctor rotates, the slots change the magnetic field to sensor, creating an induced voltage.

Fig 1: 2.5L Direct Ignition System (DIS) Components
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