Antilock Brakes / Traction Control Systems: Description and Operation

Anti-Lock Control
The ABS consists of the following components:
^ ABS module
^ Hydraulic control unit (HCU)
^ Front wheel speed sensor
^ Front wheel speed sensor ring (integral to the front wheel bearing)
^ Rear wheel speed sensor
^ Rear wheel speed sensor ring (integral to the rear wheel bearing)
^ Traction control switch

ABS prevents wheel lock-up by monitoring the wheel speed sensors and actuating HCU modulating the brake pressure to prevent wheel lockup. By preventing the wheels from locking up, the driver is able to maintain steering control and stop in the shortest possible distance under most conditions. The traction control system is controlled by the PCM and utilizes the ABS module for wheel speed information only. Engine only traction control (EOTC) helps maintain vehicle control during acceleration by modulating engine torque when driving on slippery or loose surfaces.

The front wheel speed sensor rings are integral to the front wheel bearing.

The rear wheel speed sensor rings are integral to the rear wheel bearing.