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:

    Fuel E85 (85% Ethanol)
    Vehicles that have a FlexFuel badge and a yellow fuel cap can use either unleaded gasoline or ethanol fuel containing up to 85% ethanol (E85). See Fuel E85 (85% Ethanol) . For all other vehicles, use ...

    Checking the Fluid Level
    Prepare the vehicle as follows: 1. Park the vehicle on a level place. Keep the engine running. 2. With the parking brake applied, place the shift lever in P (Park). 3. With your foot on the bra ...

    StabiliTrak® Indicator Light
    This warning light should come on briefly when the engine is started. During most driving conditions, this light will not come on. If the StabiliTrak® System is actively controlling the sta ...