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:
Electrical
...
Calculating the Route
This section describes how to calculate your route.
1. Select Set as Dest.
► The system calculates and
displays the route line on the
map screen.
The following items are available:
• R ...
Changing Your Route
DEST button (when en route)
This section describes how to alter your route, add an interim “waypoint”
(pit stop),
choose a different destination, cancel your current destination, and continue ...