See also:

Parade Dimming
This feature automatically prohibits the dimming of the instrument panel displays in daylight while the headlamps are on so that the displays are still able to be seen. ...

Automatic Transmission Shift Lock Control Function Check
WARNING When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured. 1. Before starting this check, be sure there is enough room around ...

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 ...