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. ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment on page 9‑112. Added electrical equipment ma ...

Three-Way Calling
Three-way calling must be supported on the cell phone and enabled by the wireless service carrier. 1. While on a call, press . 2. Say “Three&-way call.” 3. Use the dial or call command to ...