Hi I'm having a confusing problem with my 1997 (r) E240 All works fine for a few days then the key will not remotely unlock/lock and I have to use the metal slide out key. The dash door lock switch works fine and the internal boot opening switch works OK. I have fitted new battery's in the key but no results. By disconnecting the main battery + cable and re-connecting after a few seconds everything is back to normal then 4/5 day later it all stops working again - it's driving me mad. I would very much appreciate some help with this problem.