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:

    Belts
    • Belts may need replacing if they squeak or show signs of cracking or splitting. • Trained dealer technicians can inspect the belts and recommend replacement when necessary. ...

    How to Check Lubricant
    To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the fill plug hole, located on the transfer case, the vehicle will need some lubricant ad ...

    How to Check Lubricant
    To get an accurate reading, the vehicle should be on a level surface. 1500 Series A. Fill Plug B. Drain Plug All Except 1500 Series A. Fill Plug B. Drain Plug • When the differential is c ...