2004 GMC Sierra 1500 Pickup Owner's Manual - Page 249

XM™ Radio Messages (cont'd) Radio Display Message Unknown Condition Radio ID not known (should only be if hardware failure) Hardware failure Action Required 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. 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. Do not add paper labels to CDs, they could get caught in the CD player. Do not play 3 inch CDs without a standard adapter CD. If an error appears on the display, see "CD Messages" later in this section. Chk XMRcvr Playing a CD Insert a CD partway into the slot, label side up. The player will pull it in and the CD should begin playing. The CD symbol will appear on the display. If you want to insert a CD with the ignition off, first press the eject button or the DISPL knob. If you turn off the ignition or radio with the CD in the player, it will stay in the player. When you turn on the ignition or the radio, the CD will start playing, where it stopped, if it was the last selected audio source. As each new track starts to play, the track number will appear on the display. The CD player can play the smaller 8 cm single CDs with an adapter ring. Full-size CDs and the smaller CDs are loaded in the same manner. 3-85