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:
Rear Brake Shoe Replacement
caution
Frequent inhalation of brake pad dust, regardless of material composition,
could be hazardous to your health.
Avoid breathing dust particles.
...
Wheel Runout Inspection
Raise and support the vehicle.
Check for a bent or deformed wheel.
Set up the dial gauge as shown, and measure the axial runout by turning
the wheel.
...
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. ...