Depending on the length of time the power was interrupted, your system may require GPS initialization.

If initialization is not necessary, the system proceeds directly to the Startup Confirmation screen.
If the system fails to locate a sufficient number of satellites to locate your position within 10 minutes, the following screen is displayed.

If you are experiencing GPS reception problems:
Listening to Voice Guidance
MAP MENU (on map)
► VOICE
As you approach each guidance point, a pop-up window is displayed on the map
screen with instructions for you to follow. Voice guidance for each guidance
point is ...
Command Input
If the system does not understand a command or you wait too long to give a
command, it responds with “Pardon? No command was heard. Please press the talk
button and say a command.”
When you giv ...
Emissions Testing
Testing of Readiness Codes
If you take your vehicle for an emissions test shortly after the battery has
been disconnected or gone dead, it may not pass the test.
This is because of certain ‘‘r ...