Progressed over 10 years. I have two fobs.

At first the fob locked/unlocked all doors including the trunk.

Then it nothing worked on the drivers door.

Then the fob, and manual buttons, stopped working on the passenger door, didn't lock or unlock.

Then the fob and door locks stopped locking/unlocking the trunk, had to use a key.

Many years go by.

Then, the last year or so, the fobs would intermittently work on the passenger sliding door.

Then the fobbed stopped beeping when locking/unlocking and no longer opens the sliding passenger door.

So, at this time the fob and door locks/unlocks the drivers sliding door only, now there is no beeping when you lock/unlock from the fob

Not the battery, it actually never was the battery.

What else then? Not likely going to fix it, probably a fortune, unless but some strange luck, it's nothing that bad.

 

Could you bring us up to speed on how you know it was not a (FOB) battery problem ?

 

Battery was changed, and "paired" twice, or at least tried to. It was a couple years ago, I first tried, then I brought it to Ford, they couldn't and said it's an electric issue, just wanted to keep charging me $120 an hour, even if it was barely 15 min. Wasn't worth it.