See also:

Automatic Transmission Shift Lock Control System 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 ...

Shifting Into Park
WARNING: It can be dangerous to get out of the vehicle if the shift lever is not fully in P (Park) with the parking brake firmly set. The vehicle can roll. If you have left the engine running, ...

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 ...