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:

    Owner Checks and Services
    At Each Fuel Stop ○ Check the engine oil level. See Engine Oil on page 10‑10. Once a Month ○ Check the tire inflation pressures. See Tire Pressure on page 10‑51. ○ In ...

    Vehicle Overview
    GM says the Sierra 1500 Hybrid's gasoline V-8 and electric motors team up for an overall mileage improvement compared with the regular Sierra. The Sierra Hybrid is only available as a rear- or fou ...

    Gasoline Specifications (U.S. and Canada Only)
    At a minimum, gasoline should meet ASTM specification D 4814 in the United States or CAN/CGSB&-3.5 or 3.511 in Canada. Some gasolines contain an octane-enhancing additive called methylcyclopen ...