That is what my central locking is doing on the drivers door only when I try to lock it from the outside with the key. The drivers door button will only stay down when locked by key from the passenger door.

Any help appreciated.

I have the same problem i am not sure what the solution is but mine only happens on the odd occasion (3 or 4 times in a year) could just be a thing with e series i say just get it looked at by ford.

A common problem, something to do with a f**k actuator, has been a few threads on this, try a search.

What bosaw said, f**k actuator. Happens on a lot of E series because they all have that type of locking system. I think when the EF2/EL came out there was a TSB on it because i remember my parents old EF getting this fixed under warranty. The locking system was different after that.

there is a doco on fixing it well worth it IMO.

Yep, Effed actuator, but it will actually be on the passenger's side front door. The reason being is that when you use the key from the driver's side, the lock on the passenger door is being operated by the electronic lock, and the stuffed actuator, the car thinks that the passenger door is open, so the lock cycle and remain unlocked. When you use the key on the passenger side door, it's locking mechanically, so all doors will lock.