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:
How to Inspect the Engine AirCleaner/Filter
To inspect the air cleaner/filter remove the filter
from the vehicle and lightly shake the filter to
release loose dust and dirt. If the filter remains
caked with dirt, a new filter is required.
...
Audio System
When using the in-vehicle Bluetooth system, sound
comes through the vehicle’s front audio system speakers
and overrides the audio system. Use the audio system
volume knob, during a call, to ch ...
Using this Manual
To quickly locate information about the vehicle, use the Index in the back of
the manual. It is an alphabetical list of what is in the manual and the page number
where it can be found. ...