Wheel Speed Sensor: Description and Operation

SENSOR OPERATION
There are four variable-reluctance brake anti-lock sensors and brake anti-lock sensor indicators to determine the rotational speed of each wheel. The sensors operate on magnetic induction principle. As the teeth on the brake anti-lock sensor indicators rotate past the brake anti-lock sensors, a signal is generated. The frequency of the pulsating signal is proportional to the speed of the rotation is generated. The signal is sent to the anti-lock brake control module through a twisted pair harness.

SENSOR MOUNTING

Front Wheel Speed Sensor:

Front - The anti-lock brake control module front brake anti-lock sensors (2C204) are bolted to the front wheel knuckles (3K185).

Rear Wheel Speed Sensor:

Rear - On sedans, the rear brake anti-lock sensors (2C190) are attached to the rear disc brake adapter.
- On station wagons, the rear brake anti-lock sensors attach to the rear wheel spindle (4A013).

INDICATOR MOUNTING
- The front brake anti-lock sensor indicators (2C182) are pressed onto the outer CV joints.
- The rear brake anti-lock sensor indicators (2C189) are pressed onto the wheel hub (1104) assemblies.