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.
Engine oil system flushes are not recommended and could cause engine damage not covered by the vehicle warranty.
See also:
Brake Pedal Travel
See your dealer/retailer if the brake pedal does not
return to normal height, or if there is a rapid increase in
pedal travel. This could be a sign that brake service
might be required. ...
Unlock Doors
Press the customization button until UNLOCK
DOORS: IN PARK appears in the display.
To select your preference for automatic unlocking,
press the select button while UNLOCK DOORS:
IN PARK is dis ...
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 ...