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:

    Battery
    Your vehicle has a maintenance free battery. When it is time for a new battery, get one that has the replacement number shown on the original battery’s label. We recommend an ACDelco® replace ...

    Automatic Transmission Fluid
    How to Check Automatic Transmission Fluid 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 v ...

    Consistency of Readings
    Always check the fluid level at least twice using the procedure described previously. Consistency (repeatable readings) is important to maintaining proper fluid level. If inconsistent readings per ...