I've a 2015 2.5L Transit Connect with 101k miles and it's a daily driver/work van. I go to take off it in one morning a couple of weeks ago and it wouldn't start. Display said: No key detected

So I get my other two Ford key fobs and try both of those, same exact result: No key detected.

I get to checking things while continuing to swap keys and still getting a "No key detected" on the display. While screwing around doing this I note that the display shows: "Brake fluid low service soon" three different times but I cannot replicate that. Also there's no dome light or cargo light but headlights work and emergency flashers work. The horn will honk but only for one second then won't honk again, you can only hear the horn relay. But give it 20 seconds and the horn will honk again for one second and that's it, and after another 20 seconds the horn will honk again when the horn button is pushed but again for only one second. There's a very quiet intermediate clicking coming from under the dash on the passenger side. I figured a bad battery was causing this weirdness so I ultimately replaced it after two different auto parts stores both said my 2 y.o. battery was still good. No improvement with new battery. While looking around under the hood I note that my washer hose has been chewed in half. I use my w. washer daily so the washer hose getting chewed in half by a varmint happened at the exact same time as the onset of my weird electrical problem. I'm thinking the same varmint and/or it's pal chewed up some wiring. I had it towed to the Ford dealer I somewhat trust and it's taken them two weeks to get to it. They say they've looked all over it yet tell me they see no evidence of damaged wiring. They're telling me all the keys need to be re-programmed so I took the other two Ford key fobs to them.

Has anyone else with a 2014 or later Transit Connect experienced a sudden failure of the OEM Ford key fobs doing the handshake with the PCM?

 

Definitely sounds like a chewed wire somewhere, or a bad ground. If all fails, you might need to take it to a place that specializes in vehicle electrical problems.
I'm surprised that the guys that you took it to didn't scan the OBDII for clues.
damn critters can get in places you can't imagine.
Good luck.

 

Ok, so the Ford shop I mostly trust was first telling me they couldn't find any chewed up wiring (except for the headlight circuit which didn't solve the problem) it was a programming problem with the OEM key fob so I dropped off my other two OEM key fobs. Then they try telling me the battery was bad so I advised them that a brand new battery was installed only two days prior to being dropped off at their shop so I said "Keep going, it's not the battery." Ultimately they discovered a bad ground going to the body control module. I specifically asked if this was due to rodent damage - they advised there was zero indication of rodent damage causing that specific problem. I asked, "How often do you see this exact thing happen??" The told me, "Very rarely." $700 later it's back on the road.

So your guess that it was a bad ground was correct.

 

HA ! so my guess was right.. I'm glad it was found, but $700.00 stings.
But it sucks that it wasn't more secure from the factory..