VW Polo 2005 Windows Not Working

[jdragon]

Hi all,

I'm helping someone with a few repairs on their VW Polo 2005 TDI 3-door.

One of the problems is the windows are not working. I've tested the switch and there is a permanent live feed on the blue/grey wire, but when I press the buttons and test each one of the other three wires, there is no power going through them with the car running/ignition on.

Does this indicate the switch is faulty or should I start looking at the window motor instead?

[Crasher]

This system is computer controlled using the “Central Connivence System”, standard voltage and continuity tests are useless, the only way to proceed is using a diagnostic system such as VCDS.

[jdragon]

I have the scan. Just checking through it again and all I can see under Address 9 is

-------------------------------------------------------------------------------
2 Faults Found:
00896 - Trunk Lock Unit (F256)
27-10 - Implausible Signal - Intermittent
01598 - Drive Battery Voltage
07-10 - Signal too Low - Intermittent
-------------------------------------------------------------------------------

The battery died and apparently the windows stopped working around the same time, but how reliable that statement is I don't know.

I've since replaced the battery but the window problem is still there

[Crasher]

You need to check the switch inputs from the door switches using measuring blocks.

[jdragon]

I have no idea how to do that

Do you which module and the blocks numbers?

In the meantime I'll see what Google yields.

[jdragon]

I tried to get some feedback from the controller today, but no response

20210522_142336.jpg

There's a couple of resources suggesting a relay and capacitor failure could be the cause, so I'll do the repair and report back.

[jdragon]

Pleased to say this is now resolved.

I purchased the relay and capacitor from RS:
https://uk.rs-online.com/web/p/non-latching-relays/6995737/
https://uk.rs-online.com/web/p/alumi...B&gclsrc=aw.ds

To remove the exiting components I bought a solder vacuum:
https://uk.farnell.com/duratool/d01849/desoldering-iron-sucker-40w-uk/dp/2251950

Farnell do sell the relay and capacitor, but they have a 20A version (not 30A like RS).

I don't know if that will make any difference but I had the luxury of being able to split the order on my work accounts.

It's worth mentioning I stripped the motor to clean the contacts and lube the drive.

Like others have reported, the fix didn't work instantly after reassembly; so I locked and unlocked the car with the key, then again with the remote and went back to it an hour later.

I will likely service the passenger side motor too because the drivers side runs great in comparison.

[Crasher]

This illustrates the difference between DIY and doing it for a customer, the amount of hours you spent would equal more than a new controller and without warranty or even guarantee of success; nice to see it fixed.