Lee, I have the exact same thing happening with my 2016 Expedition. Won't recognize either Fob to start the vehicle. I had a technician run the diagnostics. All the codes are clear and none of the modules are defective. He had no answers for me and said he never saw anything like this before? The Fobs will unlock and even remote start the vehicle. They just won't start the vehicle when I'm siting in it.
If you are able to learn anything further, please be sure to share it as will I. Right now I have to start the vehicle with the Fob in the slot located in the center console.
I have a 2016 Expedition EL Limited that is having this same issue. Essentially the keys work intermittently to lock/unlock the vehicle. We have to move closer or to a different angle for the lock/unlock to work. Sometimes having to get almost right next to the vehicle. We also intermittantly get the "No Key Detected" message. It appears our issues are progressively getting worse.
We have replaced the batteries in the key fobs and have even purchased and programmed a new key fob. All key fobs, old and new, are having the same issues. Therefore, one would assume that the problem is in the vehicle. From the best I can determine, there is an external remote receiver module (I doubt this is the official name) that receives the signal from the key fob. I'm hoping that I can find and replace the module. My thought is that the connection between the antenna and the module or the connection between the module and the "computer" is corroded or possibly the module is starting to fail.
The problem is that I have searched the internet, forums, youtube, etc. high and low and I can not find the location of the (key fob) external receiver module for the 2016 Expeditions (and/or the Gen3s). I have found some mention that the TPMS "may" be used to receive the signal from the key fobs. But I have not been able to confirm. I have also seen that some F Series trucks, in the same age range, have a separate module. One thought I had was that because the backup key slot is in the center console, maybe the module is located under the center console. But I haven't gotten anywhere with that either.
Therefore, I am hoping that someone knows the location of the external receiver module for the 2016 Expeditions or any Gen3 Expedition. Any help would be greatly appreciated! Thanks!
