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:
Navigating Folders on an iPod or USB Device (Vehicles
without a Navigation System)
1. Press and hold or
while listening to a song until the contents of the current folder display on the radio display.
2. Press and hold
to go back to the previous folder list.
3. Press and rel ...
Radio Data System (RDS)
The Radio Data System (RDS) feature is available for use only on FM stations that broadcast RDS information. This system relies upon receiving specific information from these stations and only works w ...
Interior
The Sierra showcases two different interior designs. Work Truck and SLE
models are more utility-minded, with large controls and door handles that can be
operated while wearing gloves. The SLT offe ...