Normal Operation and Fault Conditions

Active wheel speed sensors generate a square wave signal proportional to wheel speed which is sent to the ABS module. Each wheel speed sensor is connected to the ABS module through 2 wires and a connector at each wheel speed sensor. The 2 circuits provide both sensor power and sensor signal return. When the ignition mode is set to ON, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry.