See also:

Buying New Tires
GM has developed and matched specific tires for the vehicle. The original equipment tires installed were designed to meet General Motors Tire Performance Criteria Specification (TPC Spec) ...

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. ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment. Added electrical equipment may interfer ...