F355 central locking

My F355 -95 has a central locking problem; when the lock at the left door is engaged, the right door doesn´t lock. There is a sound from the right door that sounds like it tries to lock but it doesn´t lock. Same result if I use the remote to the Bosch Locktronic, wich is the alarm that is fitted in the car. As a result of the central locking problem, the alarm doesn´t work proper either. Is there anyone that has some knowledge about this problem?