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:

    How to Reset the Engine Oil Life System
    Reset the system whenever the engine oil is changed so that the system can calculate the next engine oil change. To reset the system: 1. Turn the ignition to ON/RUN, with the engine off. 2. Press ...

    Engine Oil Change
    When the CHANGE ENGINE OIL SOON message displays, have the engine oil and filter changed within the next 1 000 km/600 mi. If driven under the best conditions, the engine oil life system might not ...

    Average Economy
    Press the trip/fuel button until AVG ECONOMY displays. This display shows the approximate average liters per 100 kilometers (L/100 km) or miles per gallon (mpg). This number is calculated based on the ...