Sensor, Wheel Speed, Front: Operation
The Wheel Speed Sensor (WSS) receives a 12-volt signal from the Antilock Brake System (ABS) module. As the wheel rotates, it converts the signal into a digital square wave and sends that signal back to the ABS module. The return message to the ABS module is a 7-14 mA signal to determine wheel speed.
The signal can be affected by an excessive air gap, however, the wheel speed sensor is mounted in a fixed position and cannot be adjusted.
A loose connection or corrosion can also affect the operation and may cause the wheel speed sensor signal to drop out at speeds less than 64 km/h (40 mph).