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:
Safety
Standard safety features include:
Four-wheel antilock brakes
Electronic stability system
Side curtain and side-impact airbags ...
Playing an MP3 or WMA (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.
...
Symbols
The RVC system may have a feature that lets the driver view symbols on the radio
screen while using the RVC. The Ultrasonic Rear Park Assist (URPA) system must not
be disabled to use the caution s ...