Using the “Delete All Name Tags” Command
This command deletes all stored name tags in the Hands-Free Calling Directory and the OnStar Turn-by-Turn Destinations Directory, if equipped.
To delete all name tags:
1. Press and hold 
for two seconds.
2. Say “Delete all name tags.”
See also:
Maintenance Replacement Parts
Replacement parts identified below by name, part number, or specification can
be obtained from your dealer.
If your vehicle has a diesel engine, see the Duramax diesel supplement for more
informa ...
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 hold.
...
Engine Hours
Press the vehicle information button until ENGINE HOURS displays. This display shows the total number of hours the engine has run. ...