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:

    Lane Departure Warning (LDW)
    The vehicle may have a Lane Departure Warning (LDW) system. Read this entire section before using the system. WARNING: The Lane Departure Warning (LDW) system does not steer the vehicle and is o ...

    Using Voice Recognition
    For vehicles equipped with the MyLink or IntelliLink infotainment system, see the separate MyLink/IntelliLink Features and Functions Guide for more information. To use voice recognition, press ...

    Reduced Engine Power Light
    This light comes on when a noticeable reduction in the vehicle’s performance occurs. The vehicle can be driven at a reduced speed when the reduced engine power light is on, but accelerati ...