Normal Operation
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
The wheel speed sensor generates a square wave signal that is sent to the ABS module. The wheel speed sensor circuitry connects to the ABS module connector C135 through 2 wires and a connector at each wheel speed sensor. When the ignition is turned to the RUN position, the ABS module carries out a self-test by sending a reference voltage through the wheel speed sensors and their circuitry to determine if they are functional. Power and ground are supplied to the wheel speed sensors from the ABS module.
The front wheel speed sensors are integral to the wheel hub and bearing assembly and have a serviceable jumper harness connecting the sensor to the main wire harness.