Offside Sliding Door Lock problem

[MartinMorgan]

I am looking for ideas to solve a problem that's developed on the offside sliding door of my '06 plated.Berlingo Multispace Desire.

After standing unused for a couple of months I've been unable to open this door from the OUTSIDE or INSIDE.

I've removed the internal door liner and managed to release the lock by pulling on the long rod, and the door then opens and closes perfectly from INSIDE and OUTSIDE until I operate the door lock either manually or by remote locking, when the same thing happens.

As the car needs to be MOT'd this is a major problem that needs to be resolved.
Can anyone help me ??

[Zion]

I'd see which part of the inner handle moves the rod, perhaps a plastic part has come off or has broken.

The outer handle only works when the lock is off, otherwise it's blocked or disconnected from pulling on that rod. It sounds like two things are wrong.

When you lock it, do you use one press of the fob button or two? Twice engages the deadbolts which stop the doors opening even from inside, maybe there's something going on with those.

If you put a search or your VIN into http://www.catcar.info then you can see an exploded diagram of the locking mechanism in the right section. Select Citroen and then M59, or use your VIN. Then drill down into sections for side door and locks.

[oilyrag]

Dodging the immediate issue, but if you present the car at the MoT with the doors unlocked then it should pass OK as the door will open and close as it should - the doors aren't usually locked/unlocked at the MoT so the problem shouldn't arise. 
 You could also try a dose of WD40 at the lock and all of the pivot/connection points and observe that the central locking mechanism moves as it should.  It might also be a corroded connection on the 'unlock' side of the wiring - I'm not sure where the door connector is though, as I don't have central locking on mine to compare!