See also:

Charging System Light
This light comes on briefly when the ignition key is turned to START, but the engine is not running, as a check to show it is working. If it does not, have the vehicle serviced by your dealer. T ...

Programming without a Recognized Transmitter (Keyless Access Vehicles Only)
If there are no currently recognized transmitters available, follow this procedure to program up to eight transmitters. This feature is not available in Canada. This procedure will take approximatel ...

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 ...