Got a 1999 840Ci. I didn't realise until recently that its supposed to have the one button window open/close feature using the key remote.
Actually I noticed by mistake that if you hold down the unlock button on the key for a few seconds all the windows (and the sunroof) open up. But if you hold down the lock button nothing happens (except that the doors lock).
Any ideas where to look? Why would the open function work but the close function not?