I apologize if this has been answered elsewhere. I have scoured the internet to try and figure out what to do.
I swapped my failing 2016 Head Unit with an equivalent 2017 Head Unit. Install went fairly easily, but when I went to enter codes, the first 10 on the list from Honda did not work. Now the unit will not permit me to enter any more. I've tried waiting the hour recommended, I've tried (unsuccessfully) to get in to developer mode to set the clock. I've disconnected the battery. NOTHING is allowing me to enter those last 4 codes.
What do I need to do (short of taking it to the dealer and paying them to fix). . . .