2003 GMC Sierra 1500 Pickup Owner's Manual - Page 276

(Volume): Turn the knob to increase or to decrease volume. The left knob controls the left headphone and the right knob controls the right headphone. SRC (Source): Press this button to select an audio source: radio, cassette tapes, CDs, DVDs, XM (if your vehicle is equipped with XMTMSatellite Radio Service), or DAB (if your vehicle is equipped with DAB) depending on your vehicles options. PROG (Program): The front passengers must be listening to something different for each of these functions to work: Press this button to go to the preset radio stations set on the pushbuttons on the main radio. When a cassette tape is playing, press this button to go to the other side of the tape. When a CD is playing in the radio, press this button to go back to the beginning of the CD. When a CD is playing in the CD changer, press this button to select a disc. v SEEK A : While listening to AM, FM1 or FM2, XM1 or XM2, DAB1, or DAB2, press the up or the down arrow to tune to the next or to the previous station and stay there. If the front radio is in use, you cannot seek through different stations. While listening to a cassette tape, press the up or the down arrow to hear the next or the previous selection. If the cassette tape on the front radio is in use, you cannot seek through different selections on a tape. While listening to a CD, press the up arrow to hear the next track on the CD. Press the down arrow to go back to the start of the current track if more than eight seconds have played. If the CD player on the front radio is in use, you cannot seek through different tracks. Theft-Deterrent Feature THEFTLOCK@is designed to discourage theft of your 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 be displayed. When the radio and vehicle are turned off, the blinking red light indicates that THEFTLOCK@is armed. With THEFTLOCK@activated, your radio will not operate if stolen. 3-1 21