Westfalia Tow Bar - Dedicated Electrics Installation

[JonnyJR]

I am looking to fit a tow bar to my A4 Avant S-line and I am going for the Westfalia tow bar and dedicated electrics.

I am confident in the mechanical fitment of the tow-bar, however not sure what to expect regarding fitting the electronics.

This page of the instructions shows locations of the connectors, is it as simple as looking in these locations and making the connections or are there some other things I should be aware of?

I shall look to do the VAG-COM coding my self once I have fitted the tow bar.

 

[Super Nintendo Chalmers]

Have you checked you don't already have it fitted? I found out very recently that my s line has the tow bar and the electrics already wired from the factory.

Have a look in your spare wheel well for the tow bar Also , within the rear valance you can pull down the electrics.

 

[JonnyJR]

I had a look and unfortunately I am not as lucky as you, I just have the standard solid bumper support, no provision for tow bar.

 

[George Crawley]

If you have tow bar prep then it's fairly straightforward, just need to code everything in when complete. If you don't have the tow bar prep then I believe it's a case of joining cables into the can-bus system, probably best using soldering rather than those quick connector things.
You can tell if you have the tow bar prep by looking under the rear valance and there should be a rectangular hole cut out where the tow ball will come out through. That will mean you have all the connections in the rear already to plug into the supplied kit. At least that's how it was on my Saloon.

 

[Super Nintendo Chalmers]

I was under the impression that tow bar prep was part of the s line package. I can't see it ok my options sticker as a specific code...possibly different for the Avant.

Good luck with it, I discovered mine a week or so ago and hired a trailer for jobs this weekend.

 

[HertS3]

Any idea what the code for tow bar prep is? Would be interested to know if I've got it

 

[JonnyJR]

If you have tow bar prep then it's fairly straightforward, just need to code everything in when complete. If you don't have the tow bar prep then I believe it's a case of joining cables into the can-bus system, probably best using soldering rather than those quick connector things.
You can tell if you have the tow bar prep by looking under the rear valance and there should be a rectangular hole cut out where the tow ball will come out through. That will mean you have all the connections in the rear already to plug into the supplied kit. At least that's how it was on my Saloon.

I have the hole cut out in the valance, so I am guessing I have all the wires there ready to make the connections with the electronics kit, I am just wondering if it is easily identifiable which wires are for the tow bar and if the connections are roughly located where the image above shows.

 

[Super Nintendo Chalmers]

Literally just been searching for it. Third link down on this search, pdf. I searched for "tow" or "trailer". https://www.google.com/url?sa=t&sou...FjACegQIBBAH&usg=AOvVaw3Rd0duK63-T1CuT9vWgyVK to

Check my options sticker and nothing listed related to tow bar.

Are 100% certain you don't have the tow bar in the spare wheel well?

 

[HertS3]

I saw elsewhere on the forum someone mention tow bar prep is standard on S Line, can I then take it for granted it's standard on the S4 Avant??

 

[HertS3]

A couple of pics attached, one behind the valance (I think), below the spare tyre and behind the battery. Other is view from under the car into the rectangular hole in the diffuser, looks a hole that's been skimmed closed??

 

[HertS3]

Literally just been searching for it. Third link down on this search, pdf. I searched for "tow" or "trailer". https://www.google.com/url?sa=t&sou...FjACegQIBBAH&usg=AOvVaw3Rd0duK63-T1CuT9vWgyVK to

Check my options sticker and nothing listed related to tow bar.

Are 100% certain you don't have the tow bar in the spare wheel well?

Looked at this list when I was trying to figure out what optional extras my car has. Tow bar codes seem to be 1D_ and 1M_ which I don't have on mine :/

I uploaded a couple of photos, not hopeful that I've got the prep!

 

[HertS3]

Definitely don't have that, just had a look, not sure about the prep though

 

[George Crawley]

If you have the hole in the valance then you should have the plug. On my saloon, the plug was located in the rear right box in the boot where the BCM2 module is located. It's a red plug and will have some foam around it, you might have to have a good search in that box, mine was fairly well hidden.
If you have that then it's just a matter of plugging the westfalia module into that and coding.

 

[HertS3]

Do you mean the diffuser? Under the boot floor there is a box of some sort with a cable into it, I thought it might be the sub. Are you saying it might be under there?

 

[George Crawley]

It may be different on the Avant. On the saloon there is a pull down flap in the rear right of the boot, in there is the BCM2 module. It's not under the floor, it is just to the right inside the boot.

 

[HertS3]

In my manual it shows what I posted above, there's a recess on the left where the detachable towbar sits, mine is empty and the hole in the diffuser appears to be blocked up so I'm guessing I don't have the prep, plus no code for it in the build codes

 

[George Crawley]

I've got a couple of photos where the plug should be

 

[Super Nintendo Chalmers]

What year is the vehicle?

 

[George Crawley]

Mine is a 2013 B8.5 Saloon

 

[airhoguk]

Mine is in the same position 2012 B8 Avant Sportline

 

[HertS3]

I don't think that I have a cubby like that on the right hand side of the Avant, will check when I get the car back from the dealer (spotted DSG oil leak and there's a PCV valve malfunction showing on diagnostics)

 

[airhoguk]

Its behind the netted part in the side of the boot area drivers side. Cover just pulls out towards the centre

 

[Boundy]

Hi Guys, I've also been thinking about fitting a towbar. If you check behind the right hand cubby in the Avant you should find a plug, here is mine on my 2011 Avant S-Line.

The 1 question I do have though is, what do I plug into it. Is there a specific part number for a towbar electric controller that will plug in without having to do any wiring?

Does this plug literally mean the electrics are plug and play with a bit of coding?

 

[George Crawley]

You can buy a whole Westfalia "Dedicated Electrics" kit which includes a Trailer Module. The kit comes with all the necessary looms to connect that module into the plug you have in your boot. Once everything is connected and installed then yes it is just a matter of coding it all in.

 

[HertS3]

Hmm I had a good rummage around there yesterday but couldn't find that foamed cable! Could it be that I don't have it or is it standard on the B8.5 S4 Avant?

 

[Sharpz44]

I`m the oppsosite and want to remove the westfalia towbar that came attached to my S4 Avant.

 

[HertS3]

LOL send it over

 

[George Crawley]

Hmm I had a good rummage around there yesterday but couldn't find that foamed cable! Could it be that I don't have it or is it standard on the B8.5 S4 Avant?

If you’ve got that rectangular hole in the valance you should have the plug as far as I’m aware. If it really isn’t in there then it just means you’ll need to splice into the CAN-BUS yourself which will all be done in that same right hand cubby, not particularly difficult, you’ll just need to ensure that your splicing is clean so as to not send any interference over the bus.

 

[HertS3]

Behind the diffuser? I've just got this sort of skimmed stuff there, couldn't see a hole

 

[George Crawley]

This hole in the plastic valance

 

[HertS3]

Oh, I have that! Guessing the plug is in there somewhere, I'll have to have another look!

 

[George Crawley]

I couldn’t find the plug the first time, it really blended in and was well out of the way in mine. I’d have another really good look in there just to make sure. That hole wouldn’t be there for any other reason, it’s part of the tow-bar prep.

 

[HertS3]

From the pic above it looks like it's down by that box (mine looked different to that, I think it's the EPB?? Says TRW on it and I think it said EPB somewhere too), looks like I might have to get my hand down there and see if I can find it

 

[George Crawley]

EPB will be your parking brake module, you need to look for your BCM2 module which is another black box with about 4 plugs going into it, might be in a slightly different location on the Avant but I don’t think so judging by others posts.

 

[George Crawley]

The BCM2 will look something like this, will be well in that cubby if anything like the saloon.

 

[HertS3]

Any idea?? Photo of the cubby, second pic is of a cable I can feel behind the bumper, stuck my hand above the exhaust pipes and could feel it there but couldn't tell if it ends in there. So confused! My BCM2 is on top left of the cubby, EPB on bottom left and the floor is solid around it so no cables going anywhere there! There is a solid loom which seems to go down where the boot lip starts, maybe it's in there but couldn't feel anything by sticking my arm through the hole in the valance.

 

[George Crawley]

If it’s not on any of the ends of looms that are disappearing off then it’s probably not there unfortunately, why you’ve got the hole in the rear valance I’m not sure, looks like there’s more access than my saloon so would have thought the plug would be easily visible. The plug is on the end of a 20cm tail coming out of the main loom, it won’t be very far from the module. Maybe a previous owner removed the whole tow-bar assembly for whatever reason?

 

[George Crawley]

That electrical tape does look like it’s been disturbed in the past and wound back on so someones has most likely been in there before? Or you have done that yourself?

 

[HertS3]

I didn't do nothing!

 

[borderlander]

Hi, @HertS3
Sorry to resurrect an old thread. Just wondering if you ever located the trailer plug in the rear cubby?
I'm hoping to fit a tow bar to my 2014 A4 Avant B8, which, like yours, appears to have trailer prep as there's the factory cutout in the valance... but I can't find a loose connector.
All the best!