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 an Advisor can run a check., and an Advisor can run a check.

    See also:

    Transmission Messages
    MANUAL SHIFT This message displays when the automatic transmission is in manual mode. See Manual Mode   for more information. TRANSMISSION HOT IDLE ENGINE Notice: Do not drive the vehic ...

    Temperature – A, B, C
    The temperature grades are A (the highest), B, and C, representing the tire's resistance to the generation of heat and its ability to dissipate heat when tested under controlled conditions on ...

    Power Door Locks
    Select Power Door Locks and the following will be displayed: - Unlocked Door Anti Lock Out - Auto Door Unlock - Delayed Door Lock ...