GM Service Manual Online
For 1990-2009 cars only

Your vehicle may have a Traction Assist System (TAS) that limits wheel spin. This is especially useful in slippery road conditions. The system operates only if it senses that one or both of the rear wheels are spinning or beginning to lose traction. When this happens, the system reduces engine power to limit wheel spin.

The traction control system is enabled every time your vehicle is started. The system will activate if it senses that any of the wheels are spinning or beginning to lose traction.

You may hear or feel the system working or notice a lack of accelerator response, but this is normal.

The Traction Assist System may operate on dry roads under some conditions. When this happens, you may notice a reduction in acceleration. This is normal and doesn't mean there's a problem with your vehicle. Examples of these conditions include a hard acceleration in a turn, an abrupt upshift or downshift of the transmission or driving on rough roads.

If your vehicle is in cruise control when the TAS begins to limit wheel spin, the cruise control will automatically disengage. When road conditions allow you to safely use it again, you may re-engage the cruise control. See Cruise Control .


Object Number: 814429  Size: A1

When the traction off light is on, the TAS is off and will not limit wheel spin. Adjust your driving accordingly.

The traction off light will come on under the following conditions:

    • The Traction Assist System is turned off, either by pressing the TAS on/off button, located on the instrument panel, or by turning off the automatic engagement feature of the TAS.
    • The transmission is in FIRST (1); TAS will not operate in this gear. This is normal.
    • The vehicle is driven on an extremely rough road. When the vehicle leaves the rough surface, slows down or stops, the light will go off and TAS will turn on again. This is normal.
    • A Traction Assist System, Anti-Lock Brake System or engine-related problem has been detected and the vehicle needs service.
    • If the vehicle has been driven with the TAS system on for long periods of time, or if the vehicle has gone through many several high speed braking maneuvers the system may be automatically disabled. The system will automatically re-enable after approximately two minutes of not using the brakes.

See Traction Off Light .

The Traction Assist System, as delivered from the factory, will automatically come on whenever you start your vehicle. To limit wheel spin, especially in slippery road conditions, you should always leave the system on. But you can turn the TAS off if you ever need to. You should turn the TAS off if your vehicle ever gets stuck in sand, mud or snow and rocking the vehicle is required. See Rocking Your Vehicle to Get It Out and If Your Vehicle is Stuck in Sand, Mud, Ice, or Snow .


Object Number: 822626  Size: A1

To turn the system on or off press the TAS on/off button located on the instrument panel.

If you used the button to turn the system off, the traction off light will come on and stay on. You can turn the system back on at any time by pressing the button again. The traction off light should go off.

If desired, for a vehicle with QUADRASTEERâ„¢, you can change the TAS automatic engagement feature so that the system will not come on automatically when the engine is started. To do so:

  1. Park the vehicle with the ignition off and the transmission in PARK (P) for an automatic transmission, or in gear for a manual transmission.
  2. Turn the ignition to RUN; do not start the engine.
  3. Apply the brake pedal, shift into NEUTRAL (N), press the accelerator pedal to the floor, then press the TAS on/off button and hold it down for at least six seconds.
  4. Release the TAS button and both pedals.
  5. Turn off the ignition and wait a few seconds.

The next time you start your vehicle, the TAS will not automatically come on. You can restore the automatic feature by repeating the same procedure. Whether the TAS is set to come on automatically or not, you can always turn the system on or off by pressing the TAS on/off button.