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 Advisor can run a check., and an Advisor can run a check.

    See also:

    Front Fog Lamp Light
    For vehicles with fog lamps, this light comes on when the fog lamps are on. The light goes out when the fog lamps are turned off. See Fog Lamps for more information. ...

    When to Check and Change AutomaticTransmission Fluid
    A good time to check your automatic transmission fluid level is when the engine oil is changed. Change the fluid and filter at the intervals listed in Additional Required Services on page 482, and ...

    Tire Pressure Monitor
    This vehicle may have a Tire Pressure Monitor System (TPMS). The Tire Pressure Monitor alerts you when a significant reduction in pressure occurs in one or more of the vehicle’s tires ...