On my 1995 520 I have been having intermittent central locking problems. Sometime the central locking works and sometime it does not. The problem started some months ago whereby occasionally the central locking acts up. It has been getting more frequent lately. I was locked in the car recently because I could not pull up the lock knob on the driver's door. It refused to go up. I had to wind down the window and do the emergency unlocking procedure with the lock which is usually done when the battery is dead.
There are no issues with the battery or any other electrical components. All four door actuators have this problem so I dont think it is the door actuators. Each time I take it to the mechanic the central locking works fine. I read somewhere it could be due to the general module below the back seat. Does anyone have any pointers on this. Appreciate it.