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:

    Driving for Better Fuel Economy
    Driving habits can affect fuel mileage. Here are some driving tips to get the best fuel economy possible. ► Avoid fast starts and accelerate smoothly. ► Brake gradually and avoid abrupt ...

    Driver Information Center (DIC)
    The Driver Information Center (DIC) displays information about the vehicle. It also displays warning messages if a system problem is detected. See Vehicle Messages  for more information. All mes ...

    Engine Oil
    To ensure proper engine performance and long life, careful attention must be paid to engine oil. Following these simple, but important steps will help protect your investment: Always use engin ...