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 ...

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 ...

Tachometer
The tachometer displays the engine speed in revolutions per minute (rpm). For eAssist vehicles, when the ignition is in ON/RUN, the tachometer indicates the vehicle status. When pointing to ...