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:
Accessories and Modifications
Modifying your vehicle, or installing some non-Honda accessories, can make it
unsafe. Before you make any modifications or add any accessories, be sure to read
the following information.
Accessor ...
Exhaust Gas Hazard
Carbon Monoxide Gas
The engine exhaust from this vehicle contains carbon monoxide, a colorless,
odorless, and highly toxic gas. As long as you properly maintain your vehicle,
carbon
monoxide gas ...
As required by the FCC
1)This device complies with Part 15 of the
FCC Rules and Canadian RSS-210/RSSGen.
Operation is subject to the following
two conditions: (1) this device may not
cause harmful interference, and (2 ...