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:

    Arming the System
    To arm the system, press on the RKE transmitter. The alarm automatically arms after about 30 seconds. The security light, located on the instrument panel, flashes. Press on the RKE transmi ...

    Setting Cruise Control
    Cruise control will not work if the parking brake is set, or if the master cylinder brake fluid level is low. The cruise control light on the instrument panel cluster comes on after the cruise co ...

    Checking Coolant
    The engine coolant recovery tank is in the engine compartment on the passenger’s side of the vehicle. The cap has this symbol on it. The vehicle must be on a level surface. When your engine ...