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:

    Treadwear
    The treadwear grade is a comparative rating based on the wear rate of the tire when tested under controlled conditions on a specified government test course. For example, a tire graded 150 would wear ...

    Reducing Speed While Using Cruise Control
    If the cruise control system is already activated: • Press and hold the SET– button on the steering wheel until the lower speed desired is reached, then release it. • To slow down in small amo ...

    Driving for Better Fuel Economy
    Driving habits can affect fuel mileage. Here are some driving tips to get the best fuel economy possible. ○ Avoid fast starts and accelerate smoothly. ○ Brake gradually and avoid abrup ...