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:
Instruments and Controls
This section gives information about the controls and displays that contribute
to the daily operation of your vehicle. All the essential controls are within easy
reach. ...
Headliner Removal/Installation (General information)
Special Tools Required
KTC Trim Tool Set SOJATP2014
*Available through the Honda Tool and Equipment Program; call 888-424-6857
SRS components are located in this area. Review the SRS ...
Warm Up TWC Removal/Installation
NOTE: If the warm up TWC is damaged internally, inspect the under-floor TWC
for debris.
Raise the vehicle on a lift.
Remove the bolts (A).
Lower the vehicle.
...