Anti-Lock Brake System (ABS) and Stability Control - Overview: Overview
The ABS and stability control systems are comprised of the following subsystems which assist the driver in maintaining control of the vehicle:
- ABS
- Curve control
- Drive away release (EPB)
- EBD
- Electric parking brake control
- ESC
- Hill start assist
- RSC
- Supplemental braking assist
- Supports adaptive cruise control
- Supports collision avoidance
- Torque vectoring control
- Traction control
- Trailer sway control
The ABS helps maintain steering control by preventing the wheels from locking up during hard braking. The ABS also includes a supplemental brake assist function providing maximum brake system pressure during a severe braking event.
The curve control system helps maintain vehicle stability during adverse maneuvers such as cornering or avoiding objects in the roadway.
The EBD system helps maintain vehicle control by keeping a balanced braking condition between the front and rear wheels.
The ESC system helps prevent skids or lateral slides by modulating brake fluid to the brake calipers and reducing engine torque.
The hill start assist system is designed to assist the driver during hill starts. Using the ABS, the hill start assist system holds the vehicle on an incline for a short time, allowing the driver to release the brake pedal and press the accelerator pedal without needing to use the parking brake.
The RSC system helps prevent excessive vehicle roll by modulating brake fluid pressure to individual brake calipers and reducing engine torque.
The supplemental braking assist system uses the hydraulic pump motor and HCU to provide additional braking assist in the event of severe vacuum loss at the brake booster.
The ABS supports the adaptive cruise control system by applying the brakes as necessary to maintain the driver-set distance gap. For information on the adaptive cruise control system, Refer to: Cruise Control - System Operation and Component Description .
The ABS supports the collision avoidance system by monitoring information and precharging the brake system to allow the vehicle to stop in the shortest distance possible. For information on the collision avoidance system, Refer to: Collision Warning and Collision Avoidance System - System Operation and Component Description .
The ABS module is the ECU for the EPB system. For information on the electric parking brake system, Refer to: Parking Brake - System Operation and Component Description .
The traction control system helps prevent loss of traction by reducing drive wheel spin during acceleration.
The trailer sway control system helps maintain vehicle stability while towing a trailer by detecting and aiding in the reduction of conditions that cause trailer sway.
Torque vectoring control uses the rear brakes to adjust the speed between the driven wheels while accelerating through a corner, forcing the front end to hug the inside of the curve and improve tire grip.
Some noise from the system and pulsations in the brake pedal are normal conditions during most ABS and stability control events. Also, longer than normal brake pedal travel may be experienced immediately following an ABS or stability control activation.