Questions regarding fitting a MFSW

Thundertracker

Thundertracker

New Member
Hello everyone,

I might not post much but I'm lurking on the forums periodically to glean ideas and tips for my car (it's pushing 313k km and still going strong without issues). Tbh I'm quite tempted in the MYP gearbox swap as they've come down in price, especially second hand, and my gearbox is starting to have issues.
But that's not why I'm here today, you see I live in France and they're isn't much in the way of retrofits in my area and the UK is quite a while away to ask the usual retrofit experts to do the job for me. As a quite handy person, I scoured the forums in search of info about fitting the MFSW off of an A6 and so off I went on the internet to look up the parts. My question is is everything compatible with each other? I'm pretty confident everything is but I figured I might ask you guys just to double check. So we have all these here:

Relay:

Steering Wheel:

Airbag:

Clockspring:

Dual relay plate:

Plus some wiring and bits and bobs. I also have a late type cruise control stalk added, as I have the loom from an early type cc stalk and as you need to remove the steering wheel to install cruise control, might as well do both at the same time.

So... will everything fit? And if possible can someone point me to some of the plugs described in the A6 MFSW fitting guide PDF that's floating around the forums? I figured the grey and blue plugs were the ones behind the instrument cluster but the names of the plugs being T32 for example, it makes things a bit difficult to figure out.
Also do I need to redo the clock spring calibration? Can I use the A6 abs info to do that? Or is there an A2 specific version I have to get from somewhere?

Oh I might remind everyone I have a 2004 1.4tdi with a full DIS display, so it is CAN enabled from what I gathered.

Sorry for the long post and thanks to anyone who might help
 
Hello all,

I'm also getting to the point of attempting the same retrofit: I've already installed a compatible slip ring that I had sourced in anticipation when I did retrofit the cruise control (also late type), so still have this to install

20240325_155038.jpgmsfw-module1.jpg
before doing some coding...

Would the 74 pages .pdf tutorial from Bob Hawtin on how to install a MFSW on a 2001+ A6 be a good reference for the wiring on an A2, esp. regarding the TRW Steuergerät (I still have to source a dual socket of sort before embarking in that task) ?

PS: the calibration of the replacement slip ring was rather straightforward, I don't recall the exact procedure but it entailed driving a little in straight line during the VCDS procedure, and after that all was good. I can dig it up if you need, but it is likely here on the forum.
 
Hello All,

I've gathered a few missing parts and am getting close to a wiring exercice to complete the long awaited retrofit an OEM style MFSW (from A8 provenance, as the first one sourced ended up being A4 rather than A6 and actually did not have suitable internals... learning by mistake I guess): I've read carefully the wiki.a2-freun.de on the topic, I've continuity tested from the 2x3 switches and horn to the slipring output and am confident that I now only need to route 3 wires from the slipring (LIN from T5d/1 to TRW/18 and power/gnd to the internal module via the extra port 2 and 3, for which I sourced an OEM connector 4B0 973 605 with a lock rather than using an hand-made one holding only by friction) and the TRW CAN module.
4B0 973 605 slip ring connector.jpg
Yet a few questions remain, in case those in the know may have some hints or recommendations:
- where shall I route and hook up the TRW connections so that it's as close to OEM as possible, esp. the CAN signals ?
- the used Audi socket I got shows the correct number 4A0 937 529 but the wires color and even size do not seem quite fitting: would it only be because of multiple use of this reference socket or an I missing something?

4A0 937 529 connector for Steuergerät.jpg
I understand I have only a few from the 18 pins to hook-up, that is if I'm not mistaken:

TRW 4A0937529 connector to be connected
1 can low
2 GND
3 Can high

10 GND
12 term 15
13 term 30
15 term 58d (light pin 17)

18 LIN bus (to slipring T5d/1)
(below full list from the a2-freun.de wiki, including heated SW, tiptronic etc.)
Steuergerät wiring.jpg
 
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Morning all,
I too am slowly moving forward with this retrofit and to answer some of @NicM questions:
I am confident that if you had an airbag from an A4 with the correct part number listed on the A2Freun.de wiki, you could use it as long as you source the correct airbag loom, with the small connector

You can zip tie or Tesa tape the additional loom to the existing loom, by following its path, for an oem look

Your connector was likely used for something else, it will have to be opened and repinned, but otherwise it's useable, mine is blue for example, the one on the wiki is tan. Otherwise the pinout you posted looks to be aligned with my findings, I just have trouble locating terminals 15, 30 and 58d

Hope this begins to give you an answer
 
Thundertracker said:
Morning all,
I too am slowly moving forward with this retrofit and to answer some of @NicM questions:
I am confident that if you had an airbag from an A4 with the correct part number listed on the A2Freun.de wiki, you could use it as long as you source the correct airbag loom, with the small connector

You can zip tie or Tesa tape the additional loom to the existing loom, by following its path, for an oem look

Your connector was likely used for something else, it will have to be opened and repinned, but otherwise it's useable, mine is blue for example, the one on the wiki is tan. Otherwise the pinout you posted looks to be aligned with my findings, I just have trouble locating terminals 15, 30 and 58d

Hope this begins to give you an answer
Click to expand...
Thank you for your reply: what triggered me to look for an other internal loom was the simplicity of plug-and-play and OEM quality for the part that is embbeded in the SW (rather than rewiring or otherwhise modifying the A4 internal loom) - then I sourced a complete A8 wheel so am all set there (internal module included). The Steuergerät connector 4A0 937 529 I find a bit odd from the existing wire tails (sizes, colors, also connections or spades that may not match an A8 application but it may well come from an other car), though I will give it a go as is.

The point I'm still wondering about before a first go is where to route and connect the external TRW module as close as OEM wiring style as reasonably possible if I can: at this point I know CAN bus goes to the autoradio (unless suggested otherwise I'll piggy-back from there), the power (15, 30, 31) I'm thinking of getting from the fuse box, and 58d either from a switched light (possibly the climate control loom) of from a fuse after some testing.
 
If you bought the A8 wheel from Ovoko, you might have bought the one I was looking to buy haha
When I talked about the loom, I was thinking of just buying the new loom, not modifying the existing one, it's plug and play basically.

The can module can be put directly in the relay box above the fuse box under the steering wheel, there should be a double plate free there, that's what I'm going to do
 
Update on the wiring afternoon session: I succesfully plugged and routed the 3 extra wires from the steering wheel to below the dash in the fuse box area (with plenty of slack), using the OEM connectors so that they nicely click for a positive lock, and tested continuity before reinstalling the wheel. No surprise when reconnecting the battery and the horn still works: so far so good.

Next I was planning to use a multimeter for helping with wiring the TRW Steuergerät CAN module: I started with undoing the light control unit for access to 58d signal... but I could not manage to pull the #17 spade (I'm still not sure how it's locked in the socket, in spite quite a bit of time fiddling with thin tools), so I'll have to "steal" it along the wire rather than piggy back it cleanly on the spade - that'll have to do I suppose.

Then while at it, as I'm also installing a Kufatec harness for heating seat, I undid the fuse box to retrofit the power of that part on fuse 13, but for the life of me could not manage to stick in the spades supplied on the Kufatec harness into the slots:
Kufatec Harness fuse spade do not fit A2 fuse 13 slot.jpg
access is minimal and it's hard to see clearly, but I suspect the spades are just too large for the A2 fuse box: has anyone experienced that, or am I just missing something?
 
NicM said:
Then while at it, as I'm also installing a Kufatec harness for heating seat, I undid the fuse box to retrofit the power of that part on fuse 13, but for the life of me could not manage to stick in the spades supplied on the Kufatec harness into the slots:
Kufatec Harness fuse spade do not fit A2 fuse 13 slot.jpg
access is minimal and it's hard to see clearly, but I suspect the spades are just too large for the A2 fuse box: has anyone experienced that, or am I just missing something?
Click to expand...
Good Evening,

I am not an electrics man but I do have some knowledge of the fuse box in your picture. I am wondering if your difficulty is you are ignoring the function of the purple locking mechanism. In common with other connectors elsewhere the purple honeycombe acts as a secondary locking mechanism to prevent the wires from being removed and I am guessing being inserted (your problem). (Watch a few YouTube videos if not familiar). To unlock slide the purple honeycombe to one side a small distance but it will likely be very reluctant to slide if not moved in years. My memory is not fresh but it slides about 2 mm.

Happy to refresh my memory and post a few pictures if it helps but I think I have done this this previously which might turn up with a search.

Andy

EDIT.
My old post to which I referred was easy to find but click the preview to get the full post.

A

Post in thread 'Fuse board locking mechanism removal'

The secondary terminal pin lock of the fuse box is a large pink plastic honeycombed box that encases every pin location.

Rear part view of fuse box.

1626217011441.png


At one end, for want of a better word is a protruding tongue (left end in picture above) that seems to play the role of lock state indicator. When the pins are locked the the outside face of the tongue is flush with the housing.

1626217155364.png


The whole honeycomb "simply" slides about 2mm to unlock.

1626217223952.png



Note the outside face of the tongue is no longer flush with the housing indicating an unlocked state. The sliding is...
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Thank you so much! These locks are as puzzles to the beotian I am in matters of these modern cars... I suppose this is the same with 4B0 973 605 TRW socket (also purple on black plastic): I'm always wary of breaking something when pushing too hard on plastic, and there is a lot of it on an A2, but my confidence has just been boosted back and am eager to learn this trick.

I guess the main issue now remains to find out where best to tap into the two CAN wires (at this point I'm inclined to tap them off the radio, the "display bus"? which appears to be the one the MFSW should be hooked up to: any suggestion or confirmation welcome...).
 
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2work said:
Good afternoon Sir,

Hope all is well. Yes of course I'm able to advise but it seems that all is resolved now.

Kind regards,

Tom
Click to expand...
Hello,

thank you for your kind help offer: woud you have a recommendation for where from getting the CAN but signals to the TRW Steuergerät module in the fuses area (e.g. tap into the wires of the radio, or rather from somewhere else)?

Nic
 
NicM said:
Hello,

thank you for your kind help offer: woud you have a recommendation for where from getting the CAN but signals to the TRW Steuergerät module in the fuses area (e.g. tap into the wires of the radio, or rather from somewhere else)?

Nic
Click to expand...
Hi Nic,

Here’s where I’ve picked up the CAN at the instrument cluster in the past:

For Half DIS instrument clusters:
IMG_9072.jpeg


For Full DIS instrument clusters
IMG_9073.jpeg


The other connector can also be quite useful but no CAN
IMG_9070.jpeg


Hope this helps.

Kind regards,

Tom
 
Thank you for your prompt reply Tom.

Though I must admit I'm a bit hesitant to touch the instrument cluster (that I have not damaged - yet)

Would you think splicing a twister pair from the radio to the fuse box area may work? this route (about 40cm I would say) at least I have a clear vision of how to achieve it...
 
NicM said:
Thank you for your prompt reply Tom.

Though I must admit I'm a bit hesitant to touch the instrument cluster (that I have not damaged - yet)

Would you think splicing a twister pair from the radio to the fuse box area may work? this route (about 40cm I would say) at least I have a clear vision of how to achieve it...
Click to expand...
Hi Nic,

Yes from the head units 20 pin black connector would be fine just fine. There is a limit to the length of the different speed CAN looms but you’ll be nowhere near its limit. Be careful how you get to the fuse box area as you wouldn’t want any wires somehow being entangled in the steering column. My preferred route would be up and over the steering column where the instrument cluster is. You would need to remove the cluster but can leave it plugged but it will hinder access.

Kind regards,

Tom
 
An afternoon of knuckle scratching and to my surprise the MFSW works! almost upon first try should I add ;)

Thank you so much to everyone, this forum is really helping and empowering, I would certainly never have dared embarking in that retrofit without A2OC...

Since the connections had similar requirements I did the heated seats wiring at the same time:
I did not push my luck to taking out the instrument cluster, so I soldered the required wires from the light switch socket (58d on pin 17), power Term 30 through fuse 13 (thanks to the trick for unlocking the fuse box!) then on the large red wire on fuse 40A, got the ground from inside the A-pillar bolt using the eyelet, and pulled what I believe is term15 (+12V after ignition) from a somewhat thick black/blue wire coming from the contact area under the steering wheel, which had already been tapped by a previous owner to install an aftermarket radio. I pulled the CAN from the radio adapter (since I had installed a Bluemusic module), so no butchering of the OEM harness there, and routed the twisted pair to the fusebox area below the steering column. All mid wire solder pick-up points were wrapped in adhesive fabric after isolation and stress relieved whenever applicable or possible.

Regarding the heated seat I was surprised that the sliders light went on even before I connected the term 15 wire (I'm not sure what this is for then), but I did hook it up nevertheless (I did not have time to fully complete that installation as I still have to route the seat sockets to connect each seat to the climate control unit). I noted at some point that the sliders did not always get lit simultaneously with the rest of the climate control (or radio), maybe a second or two apart, but this could be before everything was hooked up.

---edit---- I finished off the wiring of the heated seats today after an other couple hours of skin scratching... The Kufatec cables are of adequate length and well made which is pleasant, as routing them through the tunnel to the driver side then across is not the most confortable task - anyway, all is done now, and tested (they don't seem to heat up very quickly but after a few minutes they do get pretty warm).

As for the MFSW I labelled the required wires on the used socket, soldered them in situ to their respective signals or power and isolated the remaining tails, then plugged the socket in the empty row above the existing relays: tight fit but everything is well tucked in place. I pulled the power (term30) from the light switch socket for the MFSW (term 30 on pin 15) since I did not have suitable blades to set an other fuse up.
Upon the first try I had EPC light on, from having turned the power on without the relays I suppose (when I was doing partial tests and looking for a Term15 pickup point), but after clearing DTC all was good (I suppose I had already set the required coding or adaptation if any when I installed the Bluetooth module, could not remember, but I did not have to do anything VCDS wise to control the radio from the buttons, all 6 worked right away).

The lighting of the steering wheel buttons is rather weak and I was not sure it worked at first, but I suppose it's because it's 25 year old...

I'm very pleased !
 
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