I am no longer able to use the central locking system on my 2003 EX. Neither the key fob control nor any of the interior locking rocker switches will lock the doors.
The same key fob will unlock the doors though, as will the interior rocker switches. The trunk release also works from the key fob. Any clues would be greatly appreciated.

 

sounds like maybe the multiplex unit is thinking a door is open (ala defective door switch) and won't let the doors lock.