See also:

Entering the Feature Settings Menu
1. Turn the ignition on and place the vehicle in P (Park). To avoid excessive drain on the battery, it is recommended that the headlamps are turned off. 2. Press the customization button to enter th ...

Antilock Brake System (ABS) Warning Light
For vehicles with the Antilock Brake System (ABS), this light comes on briefly when the engine is started. If the light does not come on, have it fixed so it will be ready to warn if there is a ...

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 ...