1997 GMC Sonoma Owner's Manual - Page 131

CD AUX: To switch between the player and the radio when a disc is playing, press the AM-FM button. To return to the player, press CD AUX. When a disc is playing, the letters CD and the CD symbol will appear on the display. (If the radio is turned off, the disc stays in the player and will resume playing at the point where it stopped.) EJECT Press this button to eject the disc from the player and play the radio. When the same or anew disc is inserted, the disc will start playing on track one. If a compact disc is left sitting in the opening for more than a few seconds, the player will pull the CD back in. The radio will continue playing. When the ignition is off, press this button to load a CD. If you leave acompact disc in the player while listening to the radio, it may become warm. Theft-Deterrent Feature THEFTLOCK" is designed to discouragetheft of your radio. It works by using a secret code to disable all radio functions whenever battery power is removed. The THEFTLOCK feature forthe radio may be used or ignored. If ignored, the system plays normally and the radio is not protected by the feature. If THEFTLOCK is activated, your radio will not operate if stolen. When THEFTLOCK is activated, the radio will display LOC to indicate alocked condition anytime battery power is removed. If your battery loses power for any reason, you must unlock the radio with the secret code before it will operate. Activating the Theft-Deterrent Feature The instructionswhich follow explain how to enter your secret code to activate the THEFTLOCK system. It is recommended that you read through all nine steps before starting the procedure. NOTE: If you allow more than 15 seconds to elapse between any steps, the radio automatically reverts to time and you must start the procedure over at Step 4. 3-17