Anti-Lock Braking System (ABS)

Anti-Lock Control

The Anti-Lock Brake System (ABS) modulates brake pressure on each wheel independently to maintain vehicle stability during braking. The ABS continually monitors the rotational velocity of each wheel anytime the ignition switch is in the run position and determines if a tire is skidding when the brakes are applied. Only then does the ABS intervene to modulate the brake pressure to the skidding wheel. The modulation continues until the wheel rotates freely. The brake pressure is then restored and the modulate/restore cycle is repeated whenever skidding is detected. This cycle occurs at a rate of several times per second.

The ABS module is capable of detecting the following system conditions

Hydraulic valve failure

Wheel speed sensor failure

ABS power relay short circuit

Interconnect failures to the ABS sensors, power and ground to the ABS module

Over/under voltage conditions

The ABS provides self-diagnostics and displays failure messages via the ABS indicator in the cluster. Failure of the ABS module, for whatever reason, will not compromise the normal operation of the brake system.

Traction control is an additional function added to the ABS system. The vehicles driven wheels are continually monitored for wheel spin relative to the calculated reference speed and to each other. If wheel spin is detected, the traction control function intervenes independently of the driver, applying brake pressure to the slipping wheel and reducing the engine drive torque supply. Meanwhile, brake pressure is modulated by the traction control until traction is re-established. Traction control brake actuation is diminished above 25 mph. Above this speed traction control relies primarily on engine torque reduction.

Traction control is enabled/disabled via the traction control "ON/OFF" switch. When the switch is in the "OFF" position, the amber traction control warning lamp solidly illuminates within the instrument cluster message centre. The traction control is automatically activated when the ignition is switched on. The traction control provides self-diagnostics also via the instrument cluster message centre.

The traction control brake intervention is automatically disabled whenever the brakes exceed a temperature limit. The traction brake intervention will remain disabled until the brakes have cooled, irrespective of ignition switch position or ignition switch cycling.