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:
Radio Reception
Frequency interference and static can occur during normal radio reception if items such as cell phone chargers, vehicle convenience accessories, and external electronic devices are plugged into the ac ...
Reducing Speed While Using Cruise Control
If the cruise control system is already activated, . Press and hold the SET– button on the steering wheel until the desired lower speed is reached, then release it.
• To slow down in small amount ...
How to Check Automatic Transmission Fluid
Because this operation can be a little difficult, it may be best to have this done at the dealer service department.
If not taken to the dealer, be sure to follow all the instructions here or a false ...