GMC 2003 C4C042 Owner's Manual page 188

Adjusting the Speakers (Balance/Fade)
AUDIO: To adjust the balance between the right and
the left speakers, press and release AUDIO until BAL
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 rear speakers,
press and release AUDIO until FAD 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. L and a zero or
F and a zero will appear on the display.
To adjust both tone controls and both speaker controls to
the middle position, end out of audio mode by waiting
for the display to change to the time display. Then press
and hold AUDIO for more than two seconds until you
hear a beep. CEN will appear on the display.
Fade may not be available if you have a regular
cab model.
Radio Messages
CAL (Calibrated): Your audio system has been
calibrated for your vehicle from the factory. If CAL
appears on the display it means that your radio has not
been configured properly for your vehicle and must be
returned to the dealership for service.
LOC (Locked): This message is displayed when the
R
Theftlock system has locked up. Your vehicle must be
returned to the dealership for service.
Playing a Compact Disc
Insert a disc partway into the slot, label side up.
The player will pull it in. The disc should begin playing.
The display will show CD. If you want to insert a
compact disc with the ignition off, first press RCL or
the eject button.
If an error appears on the display, see "Compact Disc
Messages" later in this section.
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