Antilock Brakes / Traction Control Systems: Description and Operation

Anti-Lock Control

ABS
The ABS consists of the following components:
^ ABS module
^ Front wheel speed sensor
^ Front wheel speed sensor ring (integral to the front axle halfshaft)
^ Hydraulic control unit (HCU)
^ Rear wheel speed sensor
^ Rear wheel speed sensor ring (integral to the wheel bearing/hub assembly)
^ Traction control switch (TCS) (PCM controlled)

The ABS prevents wheel lock-up by monitoring the wheel speed sensors and actuating the valves in the HCU which modulates the brake pressure to the brake calipers. 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 utilizes the same components as the ABS to prevent wheel spin and help maintain vehicle control during acceleration.