See also:

General Information
For service and parts needs, visit your dealer. You will receive genuine GM parts and GM-trained and supported service people. Genuine GM parts have one of these marks: ...

Storing and Deleting Phone Numbers
The system can store up to 30 phone numbers as name tags in the Hands-Free Directory that is shared between the Bluetooth and OnStar systems, if equipped. The following commands are used to delete an ...

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. ...