Yesterday my Edge started chirping the horn every few minutes while parked. It seemed like it was chirping a code but it was different every time. The signal lights flashed while it was chirping too. When I tried to unlock with the key fob, it re-locked a second later and the fob wouldn't lock the vehicle. It would start without problems and the inside lock buttons worked.. There was nothing different on the dashboard either.
I changed the battery in the intelligent key fob (even though it still read 3V) and everything was normal again!
There was a torrential rainstorm when the problems started, maybe that played a role in the problem. The Edge had been at the dealer for the day too; I don't know if something happened there.