Crankshaft Position Sensor: Description and Operation

DISTRIBUTOR

The distributor is mounted on the rear (flywheel end) of the engine cylinder head, and is direct-driven by the camshaft at one-half crankshaft speed. An off center drive tang pinned to the distributor shaft engages with the camshaft in only one position. Rotation is counterclockwise.

The distributor houses the crankshaft position sensor (CPS) and the rotor. The secondary voltage is received from the coil and distributed through the rotor to each spark plug.

Fig. 7 Crankshaft position sensor. 1.3L/4-80.8 & 1.8L/4-109 engines:

CRANKSHAFT POSITION SENSOR

The Crankshaft Position (CPS) Sensor provides crankshaft position input to the ECA which the ECA converts to engine speed (RPM) information.

The CPS uses a disc with 4 equally spaced slots cut into it which also rotates with the distributor shaft. As the disc rotates, each slot passes through a fixed photo sensor which senses the slot and sends a signal to the ECA reflecting crankshaft rotation speed.