MQB airbag on PQ35 platform with working horn?

[roccor]

I don't have advanced coding for MFSW

[ciclo]

What model year is your Scirocco? (VIN: Tenth digit)

[roccor]

9

I had BH module for SW but it was also for simple coding. Had to replace it with CD because of LIN2.0 support (I had golf V MFSW originally)

[ciclo]

Scirocco MY '9' 2009

J527 Coil connector. (1K0953549CD, etc)


-For models without multifunction steering wheel.

This is what you have tried taking the blue/white wire to T12/8.
The horn should work if everything is connected correctly.


-For models with multifunction steering wheel.

This is with the blue and white wire in T5/4, that is, J453 Multifunction steering wheel control unit manages the signal and sends it via lin/'can' (T12/9) to J527 and this in turn to the CANBUS system so that the BCM manages the activation of relay J4 (Horns) which is powered from the SB17 fuse.

It is highly likely that your J527 does not know how to manage the signal from your new J453 Multifunction steering wheel control unit (buttons), it seems like they don't speak the same language.

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I recommend you take a look at Drive2.ru and do some reading on your J527 unit. 1K0953549CD

In any case, I recommend checking relay J4 and fuse SB17 due to the test you did with that airbag wiring in which the yellow connector with the green locking mechanism was not compatible and was incorrectly wired for your units.


Comment:
In the PQ25 it is possible to have a multifunction steering wheel and for the horn to be managed by the J453 via 'lin' to BCM, and it is also possible with the same J453 configuration for the horn to be managed directly by the BCM (without 'lin', through a independent wire).

[roccor]

So it looks like I _should_ have blue/white in T5/4 instead of T12/8 like I had from the beginning? Since you said that T12/8 is not assigned in MFSW and I have one. But again, in J527 T12/8 is used for horn...I'm lost. Strange. People seem to have successfully retrofit mk7 to mk5 steering wheel with horn, and don't know what's wrong in mine.

[ciclo]

It's a question of parts compatibility.

Your J527 unit seems to be the culprit for the horn not working with the 'New' (different platform) model of MFSW buttons you want to install (which includes the J453 unit).

The Scirocco 2009 Model Year is a deep mess because within the 2009 Model Year itself VW made changes to the parts.

Some Images:
- J527 separated from the slip ring (>> 11/2/2009)






https://es.aliexpress.com/item/1005004904832844.html

- J453.
https://es.aliexpress.com/item/1005002091961091.html
or,
https://es.aliexpress.com/i/1005001930049856.html
with,
https://es.aliexpress.com/item/1005005951938973.html


- J527 built in the slip ring. (same MY)


https://es.aliexpress.com/i/1005004523046503.html


...and now comes the fun part, the original VW diagrams, where the precision to define this amalgam of parts is conspicuous by its absence.
That is, only by doing readings with diagnostic tools and with some experience is it possible to know how the parts involved work, the diagrams are only interpretive.

...as we saw in previous post:

1-For models without multifunction steering wheel. Basic equipment. We could say that it is applicable to all Model Years.

with G85 ⬇ (for connection purposes, it is the same as the previous diagram)


2-For models with multifunction steering wheel. ('9' MY)


3-For models with multifunction steering wheel. ('A' Model Year, etc)

T12/9 = LIN, not 'can'.
T12/8 = GRA.
Compare '9' with 'A, etc' and draw your own conclusions.

...and now you say that it is strange, that in other Scirocco it works and in 'yours' 2009 it doesn't work, etc...

Have you tried a three-ground airbag with three-ground wiring with blue/white wire through pin T12/8? I imagine that it is the only possibility you have to work your horn with those NEW buttons (J453 'lin'), although it is possible that if 'your' J527 detects MFSW it will try to make the horn work through that 'can' T12/9... and the horn will not work.

IMHO, VW should have waited to launch the VW Scirocco on sale in 2010...

You can too throw your Scirocco in the trash, and buy one of those thousands of ID3s that VW has stored in infinite fields and that I think VW is going to sell in China at Aliespress prices, that is, for a third of northern European prices. The opinion of the ID3 prices for southern Europeans is this = .

[roccor]

Have you tried a three-ground airbag with three-ground wiring with blue/white wire through pin T12/8? I imagine that it is the only possibility you have to work your horn with those NEW buttons (J453 'lin'), although it is possible that if 'your' J527 detects MFSW it will try to make the horn work through that 'can' T12/9... and the horn will not work.

Just tried that, sadly no difference at all. No horn whatsoever. In measure blocks in VCDS horn is labeled as not installed.

[ciclo]

Maybe Drive2.ru user bauhax could help you, try to contact him, according to his profile he has experience in these matters.



Read the thread and his comment on the image above here. https://www.drive2.ru/l/646090075985160431/


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https://www.drive2.ru/l/580823340638273602/ , https://www.drive2.ru/l/529284557719995499/

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Button coding J453 (1K8 959 442).

On our 6R 'PQ'25 this is the coding for those buttons. (LIN ---> BCM) https://www.uk-polos.net/viewtopic.php?p=498666#p498666

Subsystem 7 - Part No SW: 1K8 959 442 HW: 1K8 959 442
Component: E221__MFL-DC1 H03 0103
Serial number: 27140003142720054516
Coding: A4FFFF

A5FFFF (with DSG)

I'm wondering if coding your multifunction steering wheel on another PQ vehicle with this coding and supporting the UDS protocol (or on a test bench) and then installing it on your Scirocco would make the horn work through your J527 with blue/white wire connected to T5/4.

Something similar must be done with the buttons of the latest platforms (touch or normal MQB buttons) so that they work on previous platforms.
(in addition to other modifications, -emulator for CCS + wire/BCM coding for the horn-)
I coded some of them on my Golf7.5 and others on my test bench and then installed them on my 6R, which due to the CCS emulator the buttons/coding are not visible in the Autoscan.

Example --> viewtopic.php?p=595902#p595902 everything works! (all buttons, horn, CCS MFSW). Previously viewtopic.php?p=588216#p588216 , https://www.uk-polos.net/viewtopic.php?p=590817#p590817

[roccor2]

I've abandoned the topic a bit for a while, I'm eager to look at the schematics you've attached and thanks for your help so far! By the way, I wanted to add another note, because I noticed that when I coded the steering wheel without multifunction buttons, then the horn works! I don't know if this could be a clue to solving the problem or if I still need to take apart the column and code the module in an older car using BCM, but in any case I am reporting what I noticed

Btw. that man you suggested to talk to said that I should pull out 8 pin and 11 pin completely (so the blue and grey one) and solder them together. And in multifunction buttons plug, pull out grey from 5 pin and put it to 4 pin. And that is making the MQB loom the PQ35 loom basically. Going to test that if that will not blow up my airbag

(sadly I had to create another account as I forgot password to the main one but password recovery is not working on this forum as I tried for the past two months)

EDIT:
Yes, indeed everything is working now! Thank you very much Ciclo for your help! Much appreciated!