See also:

Diagnostics
OnStar Vehicle Diagnostics will perform a vehicle check every month. It will check the engine, transmission, antilock brakes, and major vehicle systems. It also checks the tire pressures, if the v ...

Auto Rear Defog
If equipped, this will allow you to turn the auto rear defog on or off. This feature will automatically turn on the rear defogger when it is cold outside. Press SELECT when Auto Rear Defog i ...

Parking Brake and Automatic Transmission P (Park) Mechanism Check
WARNING: When you are doing this check, the vehicle could begin to move. You or others could be injured and property could be damaged. Make sure there is room in front of the vehicle in case it ...