Lock In

Tuesday, November 13th, 2018

So, back in July/August, while I was recovering from surgery again, I was a passenger in the Lupo more than usual, and noted the central locking unlocking and relocking the door every time we slowed and sped up.

“It’s been doing that. seems to be getting worse”

Given my less mobile state, I just broke out VCDS and disabled the automatic door locking function in the CL module.

Investigation when I was a bit recovered found that the microswitch that tells the module that the door is locked wasn’t working, so it kept trying to relock the door. This is all built into the door latch module, so it was off with the door trim again (and the car retained the stripped out rallycar look for 3 months or more- time pressures, and the non-availability of the membrane behind the trim (which is impossible to remove in one piece).

Stripped out look.

So, in theory, it’s easy. Remove a cap in the back edge of the door. Insert a T20 torx driver, and carefully unscrew just enough to pull out the lock cylinder (don’t unscrew too far, or the pingfuckits drop inside):

Door handle with lock cylinder removed.

Make sure the other door is open (!), and there, in the back edge of the handle, is a cable that connects the handle to the latch. It just flips out with a small scredriver. The internal release, and the button that pops up when unlocked are attached to the latch, which just unbolts with a 8mm spline bit in the back edge of the door. Undo the electrical connector, and lift it out:

The latch mechanism.

So then. Simple, huh? Get new mechanism, a few bolts, job done?

Nope.

Genuine ones are £160. Aftermarket ones under £20, so off the the tat bazaar for an aftermarket one, fit it.

The door won’t stay shut.

Piss about for ages, mess with the striker plate- still won’t shut. Give up, refit old one. Door shuts.

Lock door, unlock door. Door won’t open from either inside or outside. The fixing bolts, remember, are only reachable with the door open. Contemplate attacking door and/or latch with dremel, decide against that, sleep on it.

Realise, eventually, what is so well described in this video:

(this guy knows his VWs, by the way, and his videos are much better than many- less waffling)

So, after several hours, back where I started. I return the ebay mechanism, and buy a used one from Stevens VW (for about the price of the cheap aftermarket one), and fit that, only to have the same locked-out issue.

Here’s a lesson for you; that cable that attaches to the handle? Adjustment is *critical* – there’s about 4-5mm adjustment where it fits the handle- and they are not all the same. The one I got with the used latch was shorter :-/. If the cable is too tight, the door won’t open *at all*. It’s also hard to get right unless the handle is bolted back into place…

So, with the used latch, the correct cable, and some trial and error, all is well, and the central locking works correctly. Just repair the membrane with some plastic sheet, repair the broken trim clips (the trim is getting delicate, at 18 years old), and refit the trim. I’ll probably strip and repair the original latch at some point.