See also:

New for 2011
The Sierra Hybrid gets GM's OnStar 9.0 telematics system that GM says provides better voice recognition. GM also said they have worked to cut down on the amount of wind noise occupants hear. ...

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. ...

OnStar Overview
If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. The OnStar system statu ...