More data about the tailgate ajar and backup camera experiment.
As noted previously, I bought an OEM Ford part PJ7Z-19G490-B camera and an "RG58 Fakra Z Female to Fakra Z Female Coaxial RF Cable" for my '24. Both off ebay so there is the chance that is part of the problem. Ha. I tried this camera and cable on my '24 and it bricks all my other cameras, but the backup camera does work. Not sure if it was the camera or cable, but I returned the camera as I didn't want to miss the return window. I thought this was likely caused by the tailgate ajar issue and I'd have to be without backup camera until that was resolved.
I wanted more data so I pulled the tailgate out of storage, put it on a dolly and rolled it under the truck. Left all the other "tailgate removal kit" plugs in place and plugged in only the tailgate camera. With that plugged in, the backup camera works fine as do all the other cameras. Still not sure if it was the camera or cable I bought, but like I said, I returned the camera. Hopefully in the next couple weeks I'll find some time to remove the factory camera from the tailgate. Then, I'll try it with the Fakara cable I have (to determine if it's the cable or camera). If it works, I'll try to determine the part number from the factory tailgate camera and go from there.
So at this point, I don't know if the camera I bought (PJ7Z-19G490-B) was the wrong part number for my '24, was faulty, or this cable is faulty, but plugging the factory camera/camera plug proves it works fine even with the tailgate ajar issue. Happy about that.
I wanted to experiment a bit more to confirm which plug related to the tailgate ajar issue, even though all evidence pointed towards the large grey and black plugs with harness since the rest were just connector plugs. I removed each plug and hooked up the tailgate connector one at a time. No change until I plugged in both the large plugs. Once I did that, I could activate the electric tailgate release with key fob and the button on the dash (indicated by the noise from the electric tailgate release in the tailgate. The tailgate ajar light remained on, of course, but based on the info from the tech at Ford on how the tailgate ajar sensors works, I had one more experiment. The tailgate ajar sensors are within the tailgate latches themselves. They are simply checking to see if those latches are fully closed. It has nothing to do with sensing the position of the tailgate; only if those latches are fully closed. If they come open, then the sensors assume the tailgate has opened. I went to the tailgate and flipped both latches closed with my finger. Started the truck and no tailgate ajar message. Even though this was a very temporary situation, I sat and basked in the glory of that for a bit just because I've not started the truck for a month without that Tailgate Ajar message poking me in the eye. Ha. Little things. I enjoyed the lack of messages and warning lights for 10 seconds. Then I hit the tailgate open button on the dash (twice to release), heard the electric tailgate release trigger, both latches released, and my old friend, the 'tailgate ajar light', appeared as expected.
One more interesting thing that happened in the last couple weeks that, due to timing of it, I'm convinced is unrelated to the tailgate ajar message. I've started receiving a message that the 'Backup brake assist' is unavailable and to see owner's manual. Hadn't received that for all the weeks I had the tailgate off and tailgate ajar message. During my experiment plugging in the tailgate and tailgate camera, that allowed the backup lines to appear on the camera view as well as a little red indicator in a section where one of four backup sensors are located. It seemed to indicate an issue with that backup sensor. Hard to get to the plug that goes into that sensor, but tried to wiggle it and see if a connection was bad. Nothing changed. Tough situation as I'm sure Ford will say that message is related to the tailgate ajar issue and that is normal for the truck to disable 'Backup brake assist' with the tailgate off. But, I proved that is incorrect by plugging in all the factory tailgate harness, making the tailgate ajar message go away, yet still trigger the message that 'Backup brake assist' is unavailable and to see the owner's manual" when I put it in reverse along with three annoyingly loud chimes. The tailgate was on the ground by the dolly, so during all this testing, I would put the pickup into reverse, but not let the truck move, of course, but all results are valid even without the truck moving. It only cares what transmission gear is selected for the backup camera and rear sensor faults; not if the truck is actually moving.
Note that in my '24, one can disable the 'Backup brake assist' and sensors in the infotainment screen. When one does that, it will pop this message each time you put it in reverser saying "'Backup brake assist is Off'. That is a different message, but still, I went in and ensured backup assist was turned on. I turned it off, confirmed the message changed to "'Backup brake assist is Off' when putting in reverse. Then turned it back on. So for now, this seems related to one of my backup sensors not working, which they should even with the tailgate ajar message. This started after I was back from our UT trip, so there is a chance all the very rough trail driving caused on of the backups sensors to loose contact if they were not fully seated from the factory. Or, one is simply faulty. I plan to do a more details check of the harness and connectors in the coming weeks.