Traction Control

Traction Control

Traction control has the same capabilities as ASC but with the added ability to actuate the brakes of the spinning wheel. This enhances ASC by improving acceleration particularly on surfaces with uneven friction e.g. one wheel on ice the other on tarmac.

When wheelspin occurs, brake line pressure to the slipping wheel is generated, to operate that wheel's brake. The BCM achieves this by closing the cut-off solenoid valve and operating the hydraulic pump. Brake fluid is then drawn from the reservoir through the non-actuated master cylinder to the brake caliper.

A 'TRAC' amber warning light flashes on the instrument panel when the system detects a spinning wheel.

The traction control system uses a brake control modulator with nine solenoid valves: four normally open inlet valves and four normally closed outlet valves and one special isolating valve. The outlet valves control the brakes of each rear wheel individually on the traction control system.