01 focus and I've had central locking problems on and off since I bought it last August more so in the colder weather but I tried several things and then it worked 100%. But now the drivers side rear door is playing up. It won't lock with the remote or if the key is used. I have to press in the lock lever on the inside of the door to lock it.

I tried all the re-programming, re-setting stuff but to no avail.

Is the problem the rear door lock mechanism or is it all linked to the drivers door lock due to central locking? Is it a case of replacing the rear door lock to fix this?

Grateful for advice as it seems to be a common problem with the focus by all the posts about it on here.

The MK1/1.5 Focus has a known problem with water ingress to the locking solenoids.

Water gets between the window and the rubber sill trim and down into the door.

Activate the central locking and listen to each door in turn.

You should hear each doors lock cycle, if not then that lock needs a good blasting with WD40.

If that doesn't cure it then a replacement lock silenoid may be needed.

remove the top torq screw on the door lock using the straw you get with the wd40 insert the straw into the hole at a 45degree angle and give it a blast refit the screw leave 30minutes and give it a try

i had the same problem for months,heres what i did.took the postive lead off the battery for 1 minute.then put it back on.mine worked a treat..