Operation CHARM: Car repair manuals for everyone.

Wheel Speed Sensor: Description and Operation

PURPOSE
A variable reluctance sensor and toothed speed indicator ring used to determine wheel speed.

OPERATION
As the ring teeth pass by the reluctance sensor, a sine wave signal is generated and sent to the Rear Antilock Brake System (RABS) control module. The frequency of the sine wave is directly proportional to rotational wheel speed.