Special Application Services

. Severe Commercial Use Vehicles Only: Lubricate chassis components every 5 000 km/3,000 mi.

- Have underbody flushing service performed once a year.

    See also:

    TTY Users
    OnStar has the ability to communicate to the deaf, hard–of–hearing, or speech–impaired customers while in the vehicle. The available dealer–installed TTY system can provide in-vehicle acces ...

    Call Waiting
    Call waiting must be supported on the cell phone and enabled by the wireless service carrier. - Press to answer an incoming call when another call is active. The original call is placed on ...

    IntelliBeam® Intelligent High-Beam Headlamp Control System
    For vehicles with this feature, be sure to read this entire section before using it. IntelliBeam is an enhancement to the vehicle's headlamp system. Using a digital light sensor on the rearvie ...