GMC 1996 Sierra Owner's Manual page 146

If the disc comes back out and ERR appears on the
display, it could be that:
The disc is upside down.
It is dirty, scratched or wet.
There's too much moisture in the air. (Wait about an
hour and try again.)
You are driving on a very rough road.
Please contact your dealer if any error recurs or cannot
be corrected.
TAPE AUX: With a disc loaded in the player and the
radio playing, press this button once to play the compact
disc. To return to playing the radio, press AM-FM. If
both a cassette tape and CD are loaded, press TAPE
AUX to switch between the tape and compact disc.
SEEK: Press the left arrow while playing a CD
to
go
back to the start of the current track. It will go back to
the current track if more than eight seconds have played.
Press the left arrow again to go to previous tracks. Press
the right arrow to go to the next higher track on the disc.
PREV (1): Press this button to go back to the start of the
current track if more than eight seconds have played.
Press PREV again to go
to
the previous track on the disc.
PROG (2): This button is active only when you have
the 12-disc changer.
NEXT (3): Press this button to advance to the next track
on the disc.
REV (4): Press and hold this button
to
quickly
reverse
within a track (song). As the CD reverses, elapsed time
will be displayed to help you find the correct passage.
FWD (6): Press and hold this button to quickly advance
within a track (song). As the CD advances, elapsed time
will be displayed
to
help you find the correct passage.
RANDOM: Press P.SCAN to enter the random play
mode. RANDOM will appear on the display. While in
this mode, the tracks on the discs will be played in
random order. I f you press SEEK, PREV or NEXT
while in the random mode, the PREV or NEXT track
will be scanned randomly. Press P.SCAN again to turn
off RANDOM and return to normal operation.
EJECT: Press this button on the remote player to eject
a compact disc.
RECALL: Press this
button
to see what track is
currently playing. Press RECALL again within five
seconds to see how long the track has been playing.
When a new track starts to play, the track number will
also appear. Press RECALL
a
third time and the time of
day will be displayed.
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