2003 GMC Sierra 1500 Pickup Owner's Manual - Page 223

Audio System(s) Notice: Before you add any sound equipment to your vehicle - like a tape player, CB radio, mobile telephone or two-way radio - be sure you can add what you want. If you can, it's very important to do it properly. Added sound equipment may interfere with the operation of your vehicle's engine, Delphi Electronics radio or other systems, and even damage them. Your vehicle's systems may interfere with the operation of sound equipment that has been added improperly. So, before adding sound equipment, check with your dealer and be sure to check federal rules covering mobile radio and telephone units. Setting the Time for Radios without Radio Data Systems (RDS) Press and hold the HR or MIN arrow for two seconds. Then press the HR (down) arrow until the correct hour appears on the display. Pressand hold the MIN (up) arrow until the correct minute appears on the display. The time may be set with the ignition on or off. Setting the Time for Radios with Radio Data Systems (RDS) Your radio may have a button marked with an or HR to H represent hoursand an M or MN to represent minutes. Press and hold the hour button until the correct hour appears on the display. Press and hold the minute button until the correct minute appears on the display. The time may be set with the ignition on or off. To synchronize the time with an FM station broadcasting Radio Data System (RDS) information, press and hold the hour and minute buttons at the same time until RDS TIME appears on the display. To accept this time, press and hold the hour and minute buttons, at the same time, for another 2 seconds. If the time is not available from the station, NO UPDAT will appear on the display instead. RDS time is broadcast once a minute. Once you have tuned to an RDS broadcast station, it may take a few minutes for your time to update. Your audio system has been designed to operate easily and togive years of listening pleasure. You will get the if most enjoyment out of it you acquaint yourself with it first. Find out what your audio system can do and how to operate all of its controls to be sure you're getting the most out of the advanced engineering that went into it. Your vehicle may have a feature called Retained Accessory Power (RAP). With RAP, you can play your audio system even after the ignition is turned off. See "Retained Accessory Power (RAP)" under lgnition Positions on page 2-2I . 3-68