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:
Voice Pass-Thru
Voice pass-thru allows access to the voice recognition commands on the cell phone. See your cell phone manufacturer's user guide to see if the cell phone supports this feature.
To access contacts sto ...
Automatic Dimming Rearview Mirror
The vehicle may have an automatic dimming inside rearview mirror. Automatic dimming
reduces the glare from the headlamps of the vehicle behind you. The dimming feature
comes on and the indicator l ...
Connections
OnStar Hands-Free Calling allows calls to be made and received from the vehicle. The vehicle can also be controlled from a cell phone through the OnStar mobile app. See www.onstar.com for coverage map ...