1995 GMC Yukon Owner's Manual - Page 179

To Disable THEFTLOCK 1. Turn the ignition on. 2. Turn the radio off. 3. With the time showing in the display, press the 1 and 4 buttons together. Hold them down until "SEC" shows on the display. You are now ready to enter your secret code. Don't wait more than I5 seconds between any of the following steps. 4. Press MIN and "000" will appear on the display. 5 . Press the MIN button again to make the last two digits agree with your code. 6. Press HR to make the first one or two digits agree with your code. 7. Press AM/FM after you have confirmed that the code matches the one you wrote down. - will appear in the display, indicating that the '' " system is unsecured (disabled). If the code is incorrect, "SEC" will appear in the display and the system will still be secured. The radio will still operate if it is secured or unsecured. If "SEC" appears and you still want to disable the system, follow the disable procedure again and enter the correct code. How to Operate Your ETtP AM-FM Stereo Audio Compact DiscATC System This part tells you how your ETR@AM-FM stereo audio compactdisc ATC system works. 3-19