Crankshaft (18X) Sensor

The 18X signal is generated by a Hall Effect switch located in an aluminum mounting bracket and bolted to the front left side of the engine timing chain cover. The Hall Effect switch alternately grounds and opens a PCM-monitored, 12-volt circuit. An air gap separates the Hall Effect switch from a magnet. An interrupter ring containing 18 blades and spaces is mounted on the vibration damper and rotates with the crankshaft.

When the Hall Effect switch is shielded from the magnetic field generated by the magnet by one of the interrupter blades, the 12-volt, PCM-monitored circuit is not grounded by the Hall Effect switch. When the Hall Effect switch is exposed to the magnetic field, the 12-volt, PCM-monitored circuit is grounded by the Hall Effect switch. The constant grounding and opening of this circuit results in an ON-OFF signal which the PCM interprets as RPM (engine speed).