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 vehicle is equipped with the Tire Pressure Monitoring System.

If a diagnostics check is needed between e-mails, push OnStar Additional Information, and an Advisor can run a check.

    See also:

    Securing Child Restraints (Right Front Passenger Seat)
    The vehicle has airbags. A rear seat is a safer place to secure a forward-facing child restraint. See Where to Put the Restraint on page 3‑44. In addition, the vehicle has a passenger sensing ...

    Battery Voltage and Charging Messages
    BATTERY SAVER ACTIVE This message displays when the system detects that the battery voltage is dropping below expected levels. The battery saver system starts reducing certain features of the vehicle ...

    Customer Assistance Offices (U.S. and Canada)
    GMC encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail GMC, the letter should be addressed to: United States GMC Customer Assistance ...