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:
ODS Unit Replacement
Removal
Do the battery terminal disconnection procedure,
then wait at least 3 minutes before starting work.
Disconnect the passenger's side airbag harness 2P connector. ...
A/F Sensor Replacement
Special Tools Required
O2 Sensor Wrench Snap-on S6176 or equivalent, commercially available
Remove the cowl cover and the under-cowl panel.
Disconnect the A/F se ...
Honda Automobile Customer Service Contact Information
Honda Navi
American Honda Motor Co., Inc.
Honda Customer Service
Mail Stop 500-2N-7E
1919 Torrance Blvd.
Torrance, CA 90501-2746
Tel: (800) 999-1009
Fax: (310) 783-3273 ...