See also:

How to Check Automatic Transmission Fluid (3.9L Engine)
Because this operation can be a little difficult, you may choose to have this done at the dealer/retailer service department. If you do it yourself, be sure to follow all the instructions here, ...

OnStar® Steering Wheel Controls
Your vehicle may have a Talk/Mute button that can be used to interact with OnStar® Hands-Free Calling. On some vehicles, you may have to hold the button for a few seconds and give the command †...

Door Ajar Light
This light comes on in the Driver Information Center (DIC) when a door is open or not securely latched. Before driving, check that all doors are properly closed. ...