UK-POLOS.NET - THE VW Polo Forum

Hi all,

I know this is a common question (it seems that maybe the quality of VW electrical bits wasn't up to much in the early 2000s), but please don't shoot me down yet, as there are a couple of specific elements to it that I can't seem to find answers to.

First, the problem...

I bought a 2005 Polo 1.9 SDi as a super-economical commuter for a new job 90 miles away from home. It was cheap because the central locking and electric windows don't work. Easy, I thought, I've fixed both in the past in various old cars. What I hadn't counted on was the sheer mind-buggering complexity of it all. There appears to be a small computer inside the electric window motor, for goodness sake. At it's simplest (I have a Mk2 Golf as well), that's basically a switch connected to a 12v motor. But not here, apparently! Anyway, the front electric windows don't do anything from any of the three switches (rears are manual), none of the central locking works apart from the rear passenger side door, which will unlock and lock using the button on the drivers door. Also the courtesy light doesn't come on when you open the drivers door. Not impressive in a car that's not 15 years old yet.

Anyway, my understanding from various forums is that this could be down to all sorts of things. All I've done so far is investigate the drivers door. The window motor is getting power, and if you dismantle it completely and stick 12v across the motor terminals it spins beautifully. I've also taken out the wiring plugs in the door pillar and verified continuity with the connections on the motor, and also checked the fuses.

All I can think to do now is replace the motor unit itself, on the assumption that maybe the aforementioned computer is at fault. BUT I've seen people talking about this subject mention 'programming' new parts, which scares me. Can I just buy a secondhand motor unit and expect it to work, or will I need a computer and some expensive software to make the car accept it?

Also, my car is definitely a 9N (round headlights), but the motor has only two plugs in the top and that sort of spiders-web casting in the drum plastic, a bit like the later 9N3 motors. Do you know if I can get any kind of plug adapter to use the earlier motor - they're much cheaper and more common, as far as I can see. In fact, if anyone can suggest any other motor type that would be compatible I'd be massively grateful.

Finally, if anyone has any recommendations for a logical approach to diagnosing the locking, again it would be hugely appreciated.

Sorry my first post is such a giant rant/epic - I'm used to fixing things that are a bit older and a lot simpler, and I am absolutely stuck! Please help!

Sorry no definitive ideas/fixes, VCDS Lite would help you a lot without paying to have full use of it, I have been lucky and had a VW Passat 4Motion from new in 2000 until 2013 without any locking or window issues, similarly my wife had a 2002 VW Polo from new until 2015 without any locking or windows issues.

The door locks do have micro switches in them and that can mess up the locking/unlocking - that will be your problem with the interior lights not switching as well as other things.

I would not think that you could dumb down these systems by swopping with earlier parts.

One thing that I've learned, if you ever find the need to own and run any VW Group car, owning a legal version of VCDS is essential - that will probably be true for many other marques as well, so maybe we are lucky that VCDS exists as it covers all the controllers in all these cars.

I'd doubt very much if any coding is needed if you only swop/replace door modules locking or windows, that would only need doing if you replaced the other controllers - as long as you replace like with like.

Hey there,

Thanks very much for the info. Hadn't heard of VCDS before (or at least hadn't realised its significance) - seems like I will need to look into that.

Also thanks for the tip about the door lock micro-switches - had no idea - was looking in the door shut for the usual plunger switch!

I have say, while I've no idea of the exact benefits of all the extra complexity, it's hard to imagine that the trade-off when it comes to running these cars in their later years. It's certainly not environmentally very cool. Anyone trying to get this fixed at a garage is going to be quoted more than the car is worth, at which point you're looking at scrapping a perfectly good car for the sake of some minor electrical gubbins.

On a more positive note, it is at least incredibly economical (which is why I bought it!) - so far I've managed 400 miles on less than 3/4 of its teeny-tiny fuel tank!

If its a like for like replacement then it wont need recoding.

I just replaced mine