Crankshaft (3X/18X) Sensor (3.8L)

The Crankshaft Position (CKP) sensor contains 2 Hall Effect switches in 1 housing. A Hall Effect switch is a solid state switching device that produces a digital ON/OFF pulse when a rotating element passes the sensor pick-up and interrupts the sensors magnetic field. The rotating element is called an interrupter ring or blade. In this case there are two interrupter rings built into the crankshaft balancer. The outer ring and outer switch provides the Ignition Control Module (ICM) with 18X signals, or 18 identical pulses per crankshaft revolution. The inner ring and inner switch provides the ICM with 3 pulses per revolution, each 1 of different duration. This is called the sync pulse, each pulse represents a pair of companion cylinders. The ICM supplies a 12-volt and low reference circuit to the CKP sensor, and uses the 18X and sync pulses to determine the crankshaft position, by counting how many ON-OFF 18X pulses occur during a given sync pulse. With this dual interrupter ring arrangement the ICM can identify the correct pair of cylinders to fire within as little as 120 degrees of crankshaft rotation.