Hi all, I am having problems with my central locking it started off it would occasionally fail to work from a distance and i would have to use the IR on the door handle to open the car. It has gotten progressively and slowly worse over a period of about 6 months ,to a point where it no longer works from a distance and even the IR is very intermittent. I often have to use the mechanical key to get in. I am guessing this is a bad contact somewhere but don't know where it can be. Does anybody have any idea what it could be or what i could try or even how the central locking coding system works and the location of the parts involved . It works of the switch on the dashboard without any problems and the FM amplifier seems to be fine going by the radio signal and the fuse does not blow.I have changed the batterys in the keys and tested them as best i can and they seem fine. The car is a c220 estate 2003. Thanks