2006 GMC Yukon Owner's Manual - Page 292

When a CD is playing, press this button to go to the beginning of the CD. This function is inactive if the front seat passengers are listening to a CD. When a CD is playing in the six-disc CD changer, press this button to select the next CD, if multiple CDs are loaded. This function is inactive if the front seat passengers are listening to a CD. Audio Steering Wheel Controls Theft-Deterrent Feature THEFTLOCK® is designed to discourage theft of your vehicle's radio. The feature works automatically by learning a portion of the Vehicle Identification Number (VIN). If the radio is moved to a different vehicle, it will not operate and LOCKED will appear on the display. When the radio and vehicle are turned off, the blinking red light indicates that THEFTLOCK® is armed. With THEFTLOCK® activated, the radio will not operate if stolen. If your vehicle has this feature, some audio controls can be adjusted at the steering wheel. They include the following: If your vehicle has OnStar, press this button to interact with the OnStar system. See the OnStar® System on page 2-50 in this manual for more information. If your vehicle does not have OnStar, press this button to silence the system. Press it again, or any other radio button, to turn on the sound. g (OnStar®/Mute): 3-132