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:
Shifting out of Park
The vehicle is equipped with an electronic shift lock release system.
The shift lock release is designed to:
• Prevent ignition key removal unless the shift lever is in P (Park) with the shift lev ...
When to Change Engine Oil
This vehicle has a computer system that indicates when to change the engine oil and filter. This is based on a combination of factors which include engine revolutions, engine temperature, and miles dr ...
Retrieve My Number
1. Push X. System responds: “OnStar ready.”
2. Say “My Number.” System responds: “Your OnStar Hands-Free Calling number is.” ...