1999 GMC Envoy Owner's Manual - Page 159

yellowblue Disabling the Theft-Deterrent Feature Enter your secret code as follows; pause no more than 15 seconds between steps: 1. Turn the ignition to ACCESSORY or RUN. 2. Turn the radio off. 3. Press the 1 and 4 buttons together. Hold them down until SEC shows on the display. 4. Press MN and 000 will appear on the display. 5. Press MN 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 secret code you have written down. The display will show ---, indicating that the radio is no longer secured. If the code entered is incorrect, SEC will appear on the display. The radio will remain secured until the correct code is entered. When battery power is removed and later applied to a secured radio, the radio won't turn on and LOC will appear on the display. If a cassette tape is playing, press this button to play the other side of the tape. If a compact disc is playing in the console-mounted CD changer, press this button to go to the next available CD. To unlock a secured radio, see "Unlocking the Theft-Deterrent Feature After a Power Loss" earlier in this section. Audio Steering Wheel Controls You can control certain radio functions using the buttons on your steering wheel. PROG: Press this button to play a station you have programmed on the radio preset buttons on the selected band. 3-23