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 Check Automatic Transmission Fluid (4.6L Engine)
    For the 4.6L V8 engine, it is not necessary to check the transmission fluid level. A transmission fluid leak is the only reason for fluid loss. If a leak occurs, take the vehicle to your dealer/ ...

    Tire Inspection
    We recommend that the tires, including the spare tire, if the vehicle has one, be inspected for signs of wear or damage at least once a month. Replace the tire if: ► The indicators at three or ...

    Vehicle Identification Number (VIN)
    This legal identifier is in the front corner of the instrument panel, on the left side of the vehicle. It can be seen through the windshield from outside. The VIN also appears on the Vehicle C ...