2007 Chevrolet Silverado 1500 Pickup Owner's Manual - Page 290

To adjust both tone controls and both speaker controls to the middle position, first end out of audio mode by pressing another button, causing the radio to perform that function or wait five seconds for the display to return to time of day. Then press and hold AUDIO for more than two seconds until you hear a beep. CEN (center) appears on the display. To adjust both tone controls and both speaker controls to the middle position, first end out of audio mode by pressing another button, causing the radio to perform that function or wait five seconds for the display to return to time of day. Then press and hold AUDIO for more than two seconds until you hear a beep. CEN (center) appears on the display. Fade may not be available if the vehicle is a regular cab model. Adjusting the Speakers (Balance/Fade) AUDIO: To adjust the balance between the right and the left speakers, press and release AUDIO until BAL (balance) appears on the display. Then press and hold the up or the down arrow to move the sound toward the right or the left speakers. To adjust the fade between the front and the rear speakers, press and release AUDIO until FAD (fade) appears on the display. Then press and hold the up or the down arrow to move the sound toward the front or the rear speakers. To adjust balance or fade to the middle position, select BAL or FAD. Then press and hold AUDIO for more than two seconds until you hear a beep. B (balance) and a zero or F (fade) and a zero appears on the display. 290 Radio Messages CAL (Calibrated): The audio system has been calibrated for your vehicle from the factory. If CAL appears on the display it means that the radio has not been configured properly for your vehicle and must be returned to your dealer for service. LOC (Locked): This message is displayed when the THEFTLOCK® system has locked up. Take the vehicle to your dealer for service. If any error occurs repeatedly or if an error cannot be corrected, contact your dealer.