MQB airbag on PQ35 platform with working horn?

[roccor]

Hello. I know this is Polo forum, but here's no offtopic category to write about things for other VWs so I'm writing here. I would write a private message to @ciclo but as new member I can't.

I have a Scirocco and I just bought golf MK7 style steering wheel. I couldn't find MK7 style airbag for scirocco anywhere so I bought one from golf MK7. It's the same scenario as for Polo 6C SW retrofit. It's from newer platform so everything works, but not horn. I saw somewhere here tutorials how to swap/solder wires for make that work but they were for different scenarios and I would like to have 100% sure to make it properly for Scirocco and not detonate airbag in front of my face somehow. Can someone provide me a proper instruction for that? Thank you very much in advance. Here is my airbag (two ground points):

[prtvrk]

In mqb, horn goes to connector via msfw buttons, on pq this is unnecessary step. Reroute horn wire to go straight into airbag connector

[roccor]

And that's what I'm kindly asking here for. My buttons are already working, but not horn. What and how to wire? Which one and where?

[ciclo]

Take out the T5/4 wire (blue/white) and cut* the terminal *(if needed in your case). Add/crimp the correct terminal, --> MQS.
Insert the wire with the MQS terminal into T12/8.

Similar to this:

[ciclo]

In mqb, horn goes to connector via msfw buttons, on pq this is unnecessary step. Reroute horn wire to go straight into airbag connector

It depends on the model and equipment. There are different versions on all platforms, including MQB.

[roccor]

Take out the T5/4 wire (blue/white) and cut* the terminal *(if needed in your case). Add/crimp the correct terminal, --> MQS.
Insert the wire with the MQS terminal into T12/8.

Similar to this:

Thank you very much for fast response! I have a white wire in there, already. On first picture I already pulled out blue/white cable as you can see, but what's that white wire for and how should I wire blue/white in this situation?

[iichel]

it looks like T12/8 is occupied by the white cable, from T5/5 (cruise control signal). you can remove T12/8 an run a new wire to the horn plate.
or, cheat a little bit and remove T5/5 and connect it to to T5/4.

I'd do the first, do it properly. But for testing, you can connect T5/5 with T5/4.

[roccor]

it looks like T12/8 is occupied by the white cable, from T5/5 (cruise control signal). you can remove T12/8 an run a new wire to the horn plate.
or, cheat a little bit and remove T5/5 and connect it to to T5/4.

I'd do the first, do it properly. But for testing, you can connect T5/5 with T5/4.

That would make sense. I have cruise control in stalk, not on steering wheel and I believe in golf VII where this airbag came from is the opposite. So if I understand correctly, I can safely just remove entirely white cable from both connectors and just plug to the yellow connector the blue/white wire?
Just to make it clear, blue/white wire is just a ground point.

[iichel]

yes but with a small correction. blue/white is connected to ground, but only when the horn is pressed. it's a so called switched ground.

[ciclo]

Where did you buy that airbag/airbag wiring?

Do this...


...it would be interesting to see the multifunction steering wheel that you are going to install...

[roccor]

I can't use it sadly... Yellow plug doesn't match to my clock spring socket. I'm already using another airbag also without working horn, but it has another construction flaw hence I bought another one...

so...

I would like to use wiring loom from my current airbag to that new airbag...but there's a problem. Current airbag have 3 ground points, new airbag have 2 ground points. All pictures attached.

As far as I can see, in my current airbag, blue/white cable is already where it needs to be, but horn wasn't working anyway. That third ground point is also brown as the second is. What it is for?

[ciclo]

Two grounds (brown/blue-white) are for the horn (switched ground) and the other for the multifunction steering wheel control unit J453.

In some airbag wiring, the 'direct' grounds (not the switched one) are spliced into the wiring itself.
I guess that's why some airbags don't have that extra ground/earth point, in addition to because the operation of the horn is through electronic signals through the LIN.

You may need to code the way the horn works in the Steering column electronics control unit J527 or in the BCM J519.

[roccor]

Two grounds (brown/blue-white) are for the horn (switched ground) and the other for the multifunction steering wheel control unit J453.

In some airbag wiring, the 'direct' grounds (not the switched one) are spliced into the wiring itself.
I guess that's why some airbags don't have that extra ground/earth point, in addition to because the operation of the horn is through electronic signals through the LIN.

You may need to code the way the horn works in the Steering column electronics control unit J527 or in the BCM J519.

So can I use wiring loom with 3 ground points on airbag with 2 ground points and just not use one of those brown ground points?

[ciclo]

I don't know, I never had an airbag with two ground points instead of three, you can use a multimeter to determine if the ground points are correct with that three point ground wiring installed... I imagine that you will have to insulate the ground terminal that you will not use...

[ciclo]

Scirocco:
-------------------------------------------------------------------------------
Address 16: Steering wheel (J527) Labels: 5K0-953-569.clb
Part No SW: 5K0 953 521 DT HW: 5K0 953 569 AH
Component: LENKS.MODUL 016 0140
Revision: FF010042 Serial number: 20141027100353
Coding: 1012140000
Shop #: WSC 00020 999 00000
ASAM Dataset: EV_SMLSNGVOLWSXS A01004
ROD: EV_SMLSNGVOLWS.rod
VCID: 8109E38F10FC51161BD-80D4

Multifunction steering wheel control module:
Subsystem 1 - Part No SW: 1K8 959 442 HW: 1K8 959 442
Component: E221__MFL-DC1 H03 0103
Coding: A5FFFF

No fault code found.

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Try disabling/enabling Byte2 Bit2 to see what happens...