Chevrolet 2006 Avalanche Owner's Manual page 250

Radio Messages
CAL ERR (Calibration Error): The audio system has
been calibrated for your vehicle from the factory. If
CAL ERR appears on the display, it means that the radio
has not been configured properly for the vehicle and
must be returned to your GM dealer for service.
Radio Display
Message
XL (Explicit Language
Channels)
Updating
No Signal
Loading XM
CH Off Air
3-84
XM™ Radio Messages
Condition
XL on the radio display,
after the channel name,
indicates content with
explicit language.
Updating encryption code
Loss of signal
Acquiring channel audio
(after 4 second delay)
Channel not in service
LOCKED: This message is displayed when the
®
THEFTLOCK system has locked up. Take the vehicle
to your GM dealer for service.
If any error occurs repeatedly, or if an error cannot be
corrected, contact your GM dealer.
Action Required
These channels, or any others, can be blocked at a
customer's request, by calling 1-800-852-XMXM (9696).
The encryption code in the receiver is being updated, and
no action is required. This process should take no longer
than 30 seconds.
The system is functioning correctly, but the vehicle is in a
location that is blocking the XM™ signal. When you move
into an open area, the signal should return.
The audio system is acquiring and processing audio and
text data. No action is needed. This message should
disappear shortly.
This channel is not currently in service. Tune to another
channel.