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:

    Services Provided
    • Emergency Fuel Delivery: Delivery of enough fuel for the vehicle to get to the nearest service station. • Lock-Out Service: Service to unlock the vehicle if you are locked out. A remote unlock ...

    Hot Check Procedure
    Use this procedure to check the transmission fluid level when the transmission fluid temperature is between 71°C and 93°C (160°F and 200°F). The hot check is the most accurate method to check the ...

    Service Vehicle Messages
    SERVICE A/C (Air Conditioning) SYSTEM This message displays when the electronic sensors that control the air conditioning and heating systems are no longer working. Have the climate control system s ...