Vito W639 remote central locking stopped working

[amt29]

The two keys fobs for my 2016 Vito have stopped working. I can lock/unlock all front, side and rear doors using the dashboard switch, but no joy with the fobs. Have to lock the drivers door with the little fob insert key. New batteries in both fobs. Very occasionally the fob will work, so have an intermittent switch/wire problem I suspect. I wonder if one of the doors isn’t being registered as closed? Although the dash switch does lock/unlock so not sure. The interior light also comes on and goes off as normal. I have cleaned both sliding door sensors. Is there some kind of micro switch to sense the closure of the front doors? Maybe in the door lock? I have tried to take one of the locks out to check but it wasn’t straight forward. Any suggestions gratefully received!

 

[amt29]

This is now fixed, by cleaning the micro switches in each front door catch mechanism. In case it is useful the door catch mechanism part number is A6397201835. This was on my 2006 W639 Vito. Note my 2016 date in earlier post was a typo!

It was a fiddle but managed to remove the door catch mechanism on both driver and passenger sides to see if I could find the switches, which I found and cleaned. The following gives some idea of how I did it, in case useful for someone.

Once the door card was removed, and the foam lining etc, The trick to get the door catch mech out was to loosen off the metal bracket that the window mechanism slides along , just the one nearest to the door lock mechanism and enough so you can move it a few cms. To do this I took the bottom bolt off and loosened the top bolt and loosened the bolt on the bracket holding the window glass (had to open the window a little to see the window bracket bolt and held glass up with tape) then you can remove the 3 bolts holding the door catch mechanism in place, turn it to the side so you can remove the electrical plug at the bottom of it (squeeze the plug on each side to release it). It was a bit awkward with the bar that pokes up through the door to show if the door is locked - on drivers side I took it off (you can carefully push and turn it to release it from the white plastic catch it is held in). On passengers side I didn’t need to remove the bar to get it out. Now slide the door catch mechanism down to the bottom of the door, there is then room to get it out by sliding it along the bottom of the door and then up.
Once it is out you can see two wires at the bottom of the mechanism, one blue one black. These go from the internals of the electric relay etc (a sealed unit) to a micro switch. I found I could lift one part that was holding the switch and pull it out easily. I then sprayed lots of switch cleaner into the switch and activated it a few times with my finger. Put it back in place and reversed all I had done to remove the mechanism, window brackets, door card and bolts.