Central locking problem
 

My 1995 440 has central locking with a 918? alarm. Suddenly, only the passenger door responds to the central locking, either using the key in the drivers door or with the alarm keyfob. (The drivers door, rear doors and boot do not work with the keyfob)
Have checked all relevant fuses I can find (including 4 in the loom behind the glovebox) Any ideas?