2003 GMC Sierra 1500 Pickup Owner's Manual - Page 245

XMTMRadio Messages Radio Display Message XL (Explicit Language Channels) Condition XL on the radio display, after the channel name, indicates content with explicit language. Updating encryption code Loss of signal Required Action These channels, or any others, can be blocked at a customer's request, by calling 1-800-852-XMXM (9696). Updating The encryption code in your receiver is updated, being and no action is required. This process should no takelonger than 30 seconds. Your is system functioning correctly, you are but in a location that is blocking the XM signal. When you move into an open area, the signal should return. Your radio system is acquiring and processing audio text data. No action is needed.Thismessageshould and No Signal Loading XM Acquiring channel audio (after 4 second delay) Channel not in service 1 CH Off Air 3-90