Unable to Connect to OnStar Message
If there is limited cellular coverage or the cellular network has reached maximum capacity, this message may come on. Push 
to try the call again or try again after driving a few miles into another cellular area.
See also:
Feature Settings Menu Items
The following customization features allow you to program settings to the vehicle:
DISPLAY IN ENGLISH
This feature will only display if a language other than English has been set. This feature allow ...
The Elephant
GMC has long combined ruggedness and elegance to good effect — consider the
Sierra pickup and Acadia crossover, for example. But the Terrain is one odd
duck. GM says it shares just a few body pa ...
Compressed Audio or Mixed Mode Discs
The radio plays discs that contain both uncompressed CD audio and MP3/WMA files depending on which slot the disc is loaded into.
The DVD Player only reads uncompressed audio and ignores MP3/WMA files ...