GMC 2010 Yukon/Yukon XL Owner's Manual page 314

Only one audio source can be heard through the
speakers at a time. An audio source is defined as
DVD slot, CD slot, XM, FM/AM, Front Auxiliary Jack,
or Rear Auxiliary Jack.
Press the button to turn the radio on. The radio can
be heard through all of the vehicle speakers.
Front seat passengers can listen to the radio (AM, FM,
or XM) by pressing the BAND button or the DVD/
CD AUX button to select CD slot, DVD slot, front,
or rear auxiliary input (if available).
If a playback device is plugged into the radio s front
auxiliary input jack or the rear auxiliary jack, the front
seat passengers are able to listen to playback from this
source through the vehicle speakers. See Using the
Auxiliary Input Jack(s) later in this section, or Audio/
Video (A/V) Jacks under, Rear Seat Entertainment
(RSE) System on page 4 125 for more information.
In some vehicles, depending on audio options, the rear
speakers can be muted when the RSA power is turned
on. See Rear Seat Audio (RSA) on page 4 134 for more
information.
4-92
Radios with a Single CD player have the capability
of playing an MP3 CD-R or CD-RW disc. For more
information on how to play an MP3 CD-R or CD-RW
disc, see Using an MP3 in the index.
Radios with a CD and DVD player have the capability of
playing an MP3/WMA CD-R or CD-RW disc. For more
information on how to play an MP3/WMA CD-R or
CD-RW disc, see Using an MP3 in the index.
Radios with a Single CD player or
radios with a Six-Disc player displays CHECK DISC
and/or ejects the CD if an error occurs.
Radios with a CD and DVD player could display other
messages when an error occurs:
The disc was inserted upside down.
A disc was inserted with an invalid or
unknown format.