GMC 2005 Savana - Manual (Page 158)

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 by waiting 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
will appear on the display.
Radio Messages
CAL (Calibration): 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 the dealer for service.
LOC (Locked): This message is displayed when the
THEFTLOCK
® system has locked up. Take the vehicle
to the dealer for service.
If any error occurs repeatedly or if an error cannot be
corrected, contact your dealer.
Radio with CD
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 the volume.
RCL (Recall): Press this knob to switch the display
between the radio station frequency and the time. When
the ignition is off, press this knob to display the time.
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