GMC 2006 Sierra - Manual (Page 305)

DVD Distortion
There may be an experience with audio distortion in
the wireless headphones when operating cellular
phones, scanners, CB radios, Global Positioning
Systems (GPS)*, two-way radios, mobile fax, or
walkie talkies.
It may be necessary to turn off the DVD player when
operating one of these devices in or near the vehicle.
* Excludes the OnStar ® System.
Cleaning the Video Screen
Pour some isopropyl or rubbing alcohol on a clean cloth
and gently wipe the video screen. Do not spray directly
onto the screen and do not press too hard or too long on
the video screen.
Rear Seat Audio (RSA)
This feature allows rear seat passengers to listen to any
of the sources: radio, cassette tapes, CDs, or DVDs.
However, the rear seat passengers can only control the
sources that the front seat passengers are not listening
to. For example, rear seat passengers may listen to
and control cassette tapes, CDs, or DVDs through the
headphones while the driver listens to the radio through
the front speakers. The rear seat passengers have
control of the volume for each set of headphones.
The front seat audio controls always have priority over
the RSA controls. If the front seat passengers switch the
source for the main radio to a remote source, the RSA will
not be able to control the source. You can operate the
rear seat audio when the main radio is off.
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