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:
Center Vent
NOTE: Take care not to scratch the dashboard or its related parts.
Remove these items:
Audio unit, without navigation system
('9-11 models)
Audio unit, with ...
How to Enter Information
You can enter information (e.g., city names, street names, personal names,
and business names comprising letters, numbers, and symbols)
when prompted on input screens by two different methods. ...
Removal
Do the battery terminal disconnection procedure.
Remove the drive belt.
Remove the intake manifold.
Disconnect the alternator connector (A) and the p ...