Crankshaft (24X) Sensor (3.1L & 3.4L)

The 24X signal is generated by a 3-wire 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 12-volt signal circuit to PCM. An air gap separates the Hall Effect switch from a magnet. An interrupter ring containing 24 equally-spaced blades 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 signal circuit is not grounded by the Hall Effect switch. When the Hall Effect switch is exposed to the magnetic field, the 12-volt signal circuit is grounded by the Hall Effect switch. The constant grounding and opening of this circuit results in an on/off signal which is interpreted by the PCM as an RPM (engine speed) signal. PCM uses the 24X signal to compute ignition timing at engine speeds less than 1200 RPM. At speeds greater than 1200 RPM, PCM uses the 3X crankshaft signal to compute ignition timing.