GMC 2003 Sierra - Manual (Page 275)

Rear Seat Audïo (RSA)
This allows rear Bsal passgngers io to any
oF the audio sources; radio, cassette lapes, CDs,
DVDs, XM (if your vehicle is equipped with
Satellite Radio Service), or DAG (if your vehicle is
equipped with DAB) depEoding on your vehicles options.
However, ihe rear seal passengers can only control
Ihe music sources Ihdl the Front ssat passengers are not
listening to. For example, near seat passengers may
listen to d cassette lape through headphones while the
driver iislens to trig radio through Ihe front speakers.
The rear seat passengers have cofilrol ot the volume for
each set of headphories- The front seat audio corilrofs
always override the RSA controls.
Rear Seat Audio Controls
The followirrg functions are controiled by Ihe RSA
system buttons;
(1^ (Power): Press this button to turn the rear seat
audio system ort or oft. The rear speakers ^111 be muted
when the power is turned on unless your vehicle is
equipped with ihe Bose'® audio system. You may
operate the near seat audio functions even when the
primary radio power is off.
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