After you have pushed the blue OnStar button and requested a Turn-by-Turn route, voice instructions begin playing after your call with the OnStar advisor has ended. Simply follow the directions as they guide you to your destination.
There are commands you can use while following your route, which you can initiate by pushing the phone or white-dot button. These commands can be found in the Quick Reference Card accompanying the OnStar manual in your vehicle glove box or you can download and print the Turn-by-Turn Quick Reference Card now.
Some popular commands are:
"Cancel route" — Command to the system to cancel receiving routes to a destination.
"Route preview" — Command to the system to preview the route to destination.
"Repeat" — Command to the system to repeat the last maneuver.