Traction Control

The traction control system helps maintain vehicle traction at the limits of tire adhesion. System effectiveness varies with vehicle speed, road conditions and steering inputs.

The ABS module defaults to ON when the engine is started.

The traction control switch (TCS) allows the driver to control the ON/OFF operation of the traction control system by pressing the switch for a minimum of one second, independent of the ABS function. The ABS control system cannot be switched off by the driver. The traction control system status is indicated by a traction control system warning light. An illuminated traction control warning light in the instrument cluster indicates that the system has been switched off by the traction control switch, or a system error has been detected and the system function is disabled. A flashing warning light indicates that wheel slip has occurred. The warning light remains flashing until traction control intervention is no longer required.

The ABS module communicates with the powertrain control module (PCM) requesting assistance with traction control. At speeds under 40 km/h (25 mph) the ABS module requests the PCM to reduce engine torque, while simultaneously applying and releasing the appropriate brake to restore traction when one or both drive wheels lose traction and begin to spin. The PCM accomplishes this by minor incremental ignition timing changes and fewer fuel injector pulses until the driven wheel speed returns to normal and the traction control module ends the request. After the vehicle speed exceeds 40 km/h (25 mph), the traction control is accomplished only by the PCM controlling the torque.

During a traction control event, you may experience any of the following normal behaviors:

• A rumble or grinding sound much like ABS
• A small deceleration of the vehicle
• The traction control indicator will flash

The ABS module continually monitors all sensors and actuators used to improve the traction control of the vehicle. Some drivers may notice a slight movement of the brake pedal when the system checks itself. If the brake system has not been bled correctly, the brake pedal movement may become more significant. The ABS function continues to work as designed unless the yellow ABS warning indicator is also illuminated. The normal brake function should always occur, unless the red brake warning indicator is illuminated.