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:
Storing the Spare Tire
WARNING
The underbody-mounted spare tire needs to be stored with the valve stem pointing down. If the spare tire is stored with the valve stem pointing upwards, the secondary latch will not work prop ...
Footnotes — Maintenance Schedule Additional Required Services — Normal
a) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properly. Replace as needed.
b) Or every four years, ...
Reporting Safety Defects to General Motors
In addition to notifying NHTSA (or Transport Canada) in a situation like this, please notify General Motors.
Call 1-800-GMC-8782 (1-800-462-8782), or write:
GMC Customer Assistance Center
P.O. Box ...