Antilock Brake System (ABS)

ANTILOCK BRAKE SYSTEM





This vehicle uses an antilock brake system designated MK25e. For this vehicle, MK25e is standard with Electronic Stability Program (ESP) and All-Speed Traction Control.

This antilock brake system uses components of the base brake system, but also features the following components:

- Integrated Control Unit (ICU) - Hydraulic Control Unit (HCU) (2) and Antilock Brake Module (ABM) (1)
- Wheel Speed Sensors (WSS) - Four sensors (one at each wheel)

The MK25e ICU is made up of the Hydraulic Control Unit (HCU) and the Antilock Brake Module (ABM). For additional information on these components, Hydraulic Control unit (HCU) - Description Anti-Lock Brake System Module - Description.

ABS

The purpose of the antilock brake system (ABS) is to prevent wheel lockup under braking conditions on virtually any type of road surface. Antilock braking is desirable because a vehicle that is stopped without locking the wheels retains directional stability and some steering capability. This allows the driver to retain greater control of the vehicle during braking.

All vehicles use Electronic Variable Brake Proportioning (EVBP) to balance front-to-rear braking when the brakes are applied in the partial braking range. For more information on electronic brake distribution, Description and Operation.

ELECTRONIC STABILITY PROGRAM

For information on the Electronic Stability Program, Description and Operation.

TRACTION CONTROL

For information on the All-Speed Traction Control, Description and Operation.

OFF-ROAD ABS

Four-wheel-drive vehicles are equipped with Off-Road ABS. Off-Road ABS provides more sustained wheel lockup than normal ABS for improved stopping performance on plowable surfaces like loose dirt, gravel, sand and mud. Such plowable surfaces move out of the way as the tires roll on them and form a wedge in front of the tires during braking because more sustained wheel lock up causes the tires to drag and the loose surface to build up in front of the tires, helping to stop the vehicle. A vehicle with normal ABS requires a longer stopping distance on the same terrain because the wheels continue rotating, not allowing the drag and build up material in front of the tires.