See also:

Reporting Safety Defects to General Motors
In addition to notifying NHTSA (or Transport Canada) in a situation like this, notify General Motors. Call 1-800-458-8006, or write: Cadillac Customer Assistance Center Cadillac Motor Car Div ...

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...

Entering the Feature Settings Menu
1. Turn the ignition on and place the vehicle in P (Park). To avoid excessive drain on the battery, it is recommended that the headlamps are turned off. 2. Press the customization button to scroll ...