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:
Passing Another Vehicle While Using Cruise Control
Use the accelerator pedal to increase the vehicle speed. When you take your foot off the pedal, the vehicle will slow down to the previous set cruise speed. ...
Using the “List” Command
1. Press and hold for two seconds.
2. Say “Directory.” 3. Say “Hands-Free Calling.” 4. Say “List.” ...
Managing the Vehicle Damage Repair Process
In the event that the vehicle requires damage repairs, GM recommends that you take an active role in its repair. If you have a pre-determined repair facility of choice, take the vehicle there, or have ...