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:
Electrical System Overload
The vehicle has fuses and circuit breakers to protect against an electrical system overload.
When the current electrical load is too heavy, the circuit breaker opens and closes, protecting the circui ...
High Voltage Devices and Wiring
WARNING
Exposure to high voltage can cause shock, burns, and even death. The high voltage components in the vehicle can only be serviced by technicians with special training.
High voltage components ...
Fuses and Circuit Breakers
The wiring circuits in your vehicle are protected from short circuits by a combination of fuses, circuit breakers and fusible thermal links.
This greatly reduces the chance of fires caused by electri ...