If your central locking unlocks itself straightaway, or the door refuses to close and lock, then try this. WD40 in the mechansim!

You do need to take the door card off to get loads into the working of the lock though. ABout 6 screws, 2 allen head bolts on the handle, take the handle off by levering the switch up and pul the black and white plugs free, take the cover off the lock pull button and the pull mechanism.

Lever the card out - about 6 push fit locators, then lastly just lift the waist rail rubber and pul the vard away and up over the button.

Now peel the plastic back in the lock area, get a nozzle on the WD40 and get load right insode the mechansim in every available area. Test and work the mechansim a few times then rebuild. It worked for me.