Honda Odyssey 2018 Owner's Manual page 304

uuAudio System Basic OperationuSystem Updates
302
5. Select Install Now or Install while
Vehicle OFF.
u A notification appears on the screen if
the update is successful.
1How to update
If Install while Vehicle OFF is selected and the user
turns the vehicle back on after the update has been
completed, for 3 to 5 minutes the system will rebuild
the applications, during which time the Honda logo
will be displayed.