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:
Wiper Blades
Check the condition of the wiper blades at least every six months.
Replace them if you find signs of cracking in the rubber, areas that are getting
hard, or if they leave streaks and unwiped areas ...
During Route Guidance
During route guidance, route information is displayed on the map/guidance
screen.
Press the MAP/GUIDE button to display the guidance screen. ...
Removal
Drain the engine coolant.
Remove the air cleaner.
Remove the heater hose clamp bracket mounting bolt (A) and the harness
holder mounting bolt (B).
...