2004 GMC Yukon Owner's Manual - Page 308

• 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 be on again. This is normal. To turn the system on or off, press the TAS on/off button located on the instrument panel. • 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 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 on page 3-46. 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" under If You Are Stuck: In Sand, Mud, Ice or Snow on page 4-50. 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, 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). 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 and 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. 4-10