Emergency Brake Assist

Advanced Emergency Brake Assist (AEBA) improves braking response during emergency braking. The AEBA is an enhancement of the electronic brake prefill and its functions controlled by the Anti-lock Brake System (ABS) control module.

For additional information, refer to: Braking Control System .

With AEBA, if the risk of a collision increases after the vehicle passes the forward alert activation threshold. The Adaptive Speed Control Module (ASCM) signals the ABS control module to activate the electronic brake prefill and EBA functions.

With AEBA the electronic brake prefill function operates in two stages:

• Stage 1:
  • Applies a brake pressure of approximately 3 bar (43.5 lbf/in² ) to all of the brakes
  • Lowers the AEBA activation threshold in the ABS control module
  • Signals to the Body Control Module/Gateway Module (BCM/GWM) assembly on the High Speed (HS) Controller Area Network (CAN) chassis systems bus to activate the stop lamps.
• Stage 2:
  • Increases the brake pressure to approximately 10 bar (145 lbf/in² ).

Stage 1 is activated if the collision risk increases to a level considered as credible, with the accelerator pedal pressed.

Stage 2 is activated when the accelerator pedal has already been released when the collision risk increases to the credible level. The two stages of electronic brake prefill are activated simultaneously, to give an immediate brake pressure of 10 bar (145 lbf/in² ).

While the second stage of electronic brake prefill is active, if the brake pedal is then pressed quickly. The ABS control module activates EBA, even if only light pressure is applied to the pedal.

EBA is available at vehicle speeds above 7 km/h (5 mph) and will function even when forward alert and adaptive speed control are switched off.

If a fault occurs in the system, a related message is displayed in the message center. AEBA will not be available until the fault is rectified.