GMC 2003 GMT560 T-Series, Owner'S Manual, Page: 106 / 284

To adjust both tone controls and both speaker controls
to the middle position, end out of audio 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
Theftlock
®
system has locked up. Your vehicle must be
returned to the dealership for service.
Radio with Cassette
Playing the Radio
PWR (Power): Press this knob to turn the system on
and off.
VOL (Volume): Turn this knob to increase or to
decrease volume.
RCL (Recall): Press this knob to switch the display
between time and radio station frequency. Time display
is available with the ignition turned off.
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