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:

    Ignition Transmission Lock Check
    While parked, and with the parking brake set, try to turn the ignition to LOCK/OFF in each shift lever position. ► For automatic transmission vehicles, the ignition should turn to LOCK/OFF only ...

    Engine Cooling System Messages
    A/C OFF DUE TO HIGH ENGINE TEMP This message displays when the engine coolant becomes hotter than the normal operating temperature. To avoid added strain on a hot engine, the air conditioning com ...

    Retained Accessory Power (RAP)
    The following accessories can be used for up to 10 minutes after the engine is turned off. • Audio System • Audio Steering Wheel (if equipped) • Clock • Power Windows • Sunroof (if eq ...