Crankshaft Position Sensor

Crankshaft position sensor, used on 3.3L and 3.8L, utilizes a Hall Effect switch mounted near vibration damper. The sensor monitors vibration damper position (crankshaft position) and sends signals to ignition module. These signals provide ECM with a TDC position reference for each piston, as well as supplying an engine speed (RPM) signal.

The 2.2L, 2.5L, 3.1L and 3.4L Direct Ignition System (DIS) and 2.3L Integrated Direct Ignition (IDI) system crankshaft position sensor protrudes through side of engine block to within .05" (1.3 mm) of an internally-mounted crankshaft reluctor ring. The reluctor ring is a special trigger wheel cast into the crankshaft. As crankshaft rotates, 7 notches in the reluctor ring change the magnetic field at the tip of the position sensor. This creates an induced AC voltage signal in the sensor windings, resulting in reference signals which are sent to ECM by ignition module. This allows ECM to compute crankshaft position and RPM and fire appropriate ignition coil at the proper time.

Vehicles equipped with HEI-EST distributor systems use the RPM reference signal from the ignition module in the distributor for a crankshaft position signal. TDC intake and TDC exhaust are not differentiated; differentiation is not necessary on non-sequential fuel injected engines. Signal is used to trigger fuel injectors. For additional information, see COMPUTER CONTROLLED COIL IGNITION (C3I) and DIRECT IGNITION SYSTEM (DIS) & INTEGRATED DIRECT IGNITION (IDI) SYSTEM under IGNITION SYSTEM.