N reg mercedes c220 central locking

[Emj79]

Hi, just got a second hand mercedes c220 and the central locking seems to have stopped working altogether, when I press the button the red/green lights on the rear view mirror and door handles flash, the indicators flash and it makes the usual pipping but none of the doors actually lock or unlock the only way I can lock/unlock the doors is by using the key on the front passenger door and leaning over to the drivers door. Any ideas on what it may be or how to fix it without having to take out a second mortgage?

Thanks

[mbtech01]

try replacing the batteries in your remote key first. The flashing green/red lights on your mirror/door handle are usually an indication that your remote keyfob batteries are weak.
If this fails to cure the problem it maybe a faulty interior rear view mirror.

[D1H]

This happened to my 1998 c180 it was the central locking vacuum pump in the boot. I got one from a breakers it was about £30 and fitted if myself it was dead easy just unclip the pipes and connect to new one.