Wheel Speed Sensor Encoders

On FWD vehicles, the wheel speed sensor encoders are several magnets arranged in a circle around one side of the wheel bearing in alternating poles. As the wheel bearing rotates the wheel speed sensor is exposed to alternating north-south magnetic fields. The encoder is part of the wheel bearing and is serviced with the wheel bearing.

On AWD vehicles, the front  wheel speed sensor encoders are several magnets arranged in a circle around one side of the wheel bearing in alternating poles. As the wheel bearing rotates the wheel speed sensor is exposed to alternating north-south magnetic fields. The encoder is part of the wheel bearing and is serviced with the wheel bearing. The rear  wheel speed sensor encoders are several magnets arranged in a circle around one side of the rear halfshaft CV joint. As the halfshaft rotates, the wheel speed sensor is exposed to alternating north-south magnetic fields. The encoder is part of the halfshaft and is serviced with the halfshaft.