Chevrolet 2003 Silverado Owner's Manual page 261

Radio Display
Message
XM Locked
Radio ID
Unknown
Chk XMRcvr
Playing a Compact Disc
If playing a CD-R the sound quality may be reduced
due to CD-R quality, the method of recording, the quality
of the music that has been recorded and the way the
CD-R has been handled. You may experience an
increase in skipping, difficulty in finding tracks and/or
difficulty in loading and ejecting. If these problems occur
try a known good CD.
XM™ Radio Messages (cont'd)
Condition
Theft lock active
Radio ID label
(channel 0)
Radio ID not known
(should only be if
hardware failure)
Hardware failure
Action Required
The XM receiver in your vehicle may have previously been
in another vehicle. For security purposes, XM receivers
cannot be swapped between vehicles. If you receive this
message after having your vehicle serviced, check with the
servicing facility.
If you tune to channel 0, you will see this message
alternating with your XM Radio 8 digit radio ID label. This
label is needed to activate your service.
If you receive this message when you tune to channel 0,
you may have a receiver fault. Consult with your dealer.
If this message does not clear within a short period of time,
your receiver may have a fault. Consult with your retail
location.
Do not add paper labels to discs, they could get caught
in the CD player.
Do not play 3 inch discs without a standard adapter disc.
If an error appears on the display, see "Compact Disc
Messages" later in this section.
3-105