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:
Languages
The vehicle can be programmed to respond in French or Spanish. Push and ask an Advisor. Advisors can speak French or Spanish. ...
Trailer Gain Adjustment Procedure
Trailer Gain should be set for a specific trailering condition and must be adjusted any time vehicle loading, trailer loading, or road surface conditions change.
Setting the Trailer Gain properly is ...
Playing an MP3/WMA File From a Disc (In Either the DVD or CD Slot)
If a disc is inserted into the top DVD slot, the rear seat operator can turn on the video screen and use the remote control to navigate the CD (tracks only).
(Tune): Turn to select MP3/WMA files.
...