2003 GMC Sierra 1500 Pickup Owner's Manual - Page 292

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, 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. This button is located on the center of the instrument panel near the radio. Press it to activate the selectable ride setting as desired. An indicator light near the button will illuminate whenever the system is active. It is recommended to use this system as follows: The next time you start your vehicle, the TAS will not automatically come on. You can restore the automatic feature by using 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. * For optimum ride comfort in an unloaded vehicle the button should be out and the indicator light will not be illuminated. This switch position indicates NORMAL levels of ride control or damping. For optimum ride comfort when trailering, fully loaded, driving off-road, or when personal preferences demand more control the button should be pressed in with the indicator light illuminated. This switch position indicates FIRM levels of ride control or damping. 0 Manual Selectable Ride The main function of this system is to provide superior ride comfort while trailering or fully loaded, as well as for unloaded driving. This system also helps to provide: Improvedtrailering stability Improved handling response when trailering or fully loaded The following guide can also be used to help determine the best setting. 4-1 1