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:
Engine Oil Additives/Engine Oil Flushes
Do not add anything to the oil.
The recommended oils with the dexos specification and displaying the dexos certification mark are all that is needed for good performance and engine protection.
Engin ...
Removing Tools
The tools needed to remove the spare tire are located in the storage compartment on the driver side, at the rear of the vehicle.
1. Open the jack storage compartment by pulling on the latch tab, loca ...
Bulb Replacement
For the proper type of replacement bulbs, see Replacement Bulbs on page 10‑45.
For any bulb-changing procedure not listed in this section, contact your dealer. ...