w210 e class central locking not always works

[nickh]

my w210 e class 1998 has an intermittant problem where by it doesnt always unlock all the doors, yet it always lock them? Also sometimes you can hear the compressor buzzing away and it cant seem to unlock anything or sometimes only one door or so unlocks?

any ideas? could it be the compressor on the way out, I have tried some existing threads but nothing yet?

 

[MB partsman]

are you always using the same key?
keys can be programmed to open just the drivers door on 1 push of the button all doors on 2 pushes, or all doors on 1 push. it may be if you are using 2 keys, that one is set differently to the other

 

[nickh]

Thanks, I tried both the keys, same thing, I am aware of the programming to just unlock drivers door etc..