[jamesfawcett]

Hi all, Ive just fitted the electric Westfalia OEM tow bar to my E91. I had to make the exhaust hanger brackets myself because BMW would not sell them separate, they would however sell me a new complete wiring loom with pins, instructions PDF and modules so I bought these (£241).

Could anyone please tell me the SA code for the electric tow bar? I'm happy to code it in myself, I just haven't found any information on it, and cant see it any of the options lists online.

For anyone wondering, its a complete pig of a job! I took the tow bar from a E90 320D in a scrap yard, I removed all the wiring which went down both sides of the car to the fuse box and various locations. If I knew it were so much work, I wouldn't have bothered

[david in germany]

Should be $235

[jamesfawcett]

Hi David, thanks but Googling I can see that:

S235A TOWING HITCH, DETACHABLE

Mines the fully electric swivelling towbar, mines not detachable - I wonder if it's the same.

[david in germany]

I will look again when I get home.

[david in germany]

Oki, electric folding should be $3AC.

[jamesfawcett]

Very very kind of you sir! Thank you very much David! I must have outdated lists, I really appreciate your help

[undecided1]

if it helps I have electric folding tow bar on my E92 and when they last updated i level 3AC was shown on the SA number listing, that should be the right code...

[jamesfawcett]

Originally Posted by undecided1

if it helps I have electric folding tow bar on my E92 and when they last updated i level 3AC was shown on the SA number listing, that should be the right code...

That does help thank you and confirms the correct code, thanks again to all that have helped and hope this helps future searchers

[Scoff123]

Hi James, I'm currently retrofitting the electric swivelling oem tow bar to my E90. Managed to get the bar and all wiring from a breakers, and gave it all a strip down and good clean up/paint ready for fitting.

Fitted the bar in place (Bloody heavy compared with the standard bar!) and fed all the wiring through into the boot but the wiring will have to wait until next weekend! I was looking at the VO code ready for when I need to code it and found S3ACA on my mates e91 which had the option from factory. Do you know if you need to make any changes in coding for PDC or anything, or is a straightforward VO code and that's it? Thanks, Scott

[jamesfawcett]

Hi Scott, I did the same! I took almost the full wiring loom from the car in the scrap yard which thankfully already had the interior removed. However, I also bought the full kit from BMW so I have two of most parts. I have the towbar compatible PDC module did you get that? I also have the cradle for it from the scrap yard that comes in the kit, which I also have new in the kit so let me know if you are missing any parts!

As for coding, I am presuming just adding the VO code to the NFRM/CAS would do it but I haven't tried yet, I haven't had any car time since our newborn has just arrived a month early, you might beat me to it at this rate!

I had to change the exhaust hanger brackets too to suit the 335 twin exhausts. It was much easier than expected I just cut the original mounts from my old bumper bar and rewelded them here:


upload my photo

Glad to find someone else doing the same as me, keep me updated on progress!

[Scoff123]

Congrats on the newborn!
I didn't realise a towbar compatible PDC module would be required - my car has factory fitted rear PDC so I wonder if it will work with the tow modules...
Don't suppose you have the part number of the PDC module that you have which is compatible do you? Hopefully I can use my existing one and maybe just code in the required params - might need to ask you for a .trc file of yours as and when you've had time to do the coding

I'll certainly give you a shout if i need any bits - thankfully all the wiring including release button that was salvaged seems to contain most of what the retrofit instructions list in the parts section. I had to modify my existing battery cover/boot trim, to fit the small grey cover/button surround, as the replacement battery cover part was not available to order anywhere according to BMW parts





I did hope to test the release/clutch mechanism before putting the bumper cover back on - but not sure if there is a quick way of applying the 12v to the motor or something in order to check it out - don't suppose you know?

[jamesfawcett]

Hi Scott, sorry not replied until now, i'll be taking another look at mine today now the weather is nicer. My wiring was a bit easier being an E91 and a later model, is yours LCI? Do you want me PDF that BMW sent me with the retrofit kit purchase it has full wiring diagrams in or do you already have it?

No problem at all about the modules I can get you a TRC file and anything else you need.

[Scoff123]

Hi James, no problem at all, figured you'd have your hands full!! My car is an E90 LCI, however the bar and wiring I got from the breakers is from a 2005 model.
I've got the BMW retrofit instructions which I've been following, however one bit I'm unsure about is where it says to tap into the rear drivers light cluster wiring. It says to connect branch A19 of the retrofit loom into the light cluster connector X318 Blue/Brown wire. I don't seem to have A19 on the loom that came with the bar? This is on page 7 of the pdf. It does however say that this step does not apply with retrofit cable set A with spare parts
no.: 61 12 0 399 478
No idea why this wouldn't apply to one particular retrofit loom, but perhaps that is the loom that came with my towbar?

[Scoff123]

Just checked the label on my loom and it is indeed part number 0399478. Not much on a Google search but curious what's different about this loom and why it doesn't need to tap into the rear light wiring?

[jamesfawcett]

Originally Posted by Scoff123

Hi James, no problem at all, figured you'd have your hands full!! My car is an E90 LCI, however the bar and wiring I got from the breakers is from a 2005 model.
I've got the BMW retrofit instructions which I've been following, however one bit I'm unsure about is where it says to tap into the rear drivers light cluster wiring. It says to connect branch A19 of the retrofit loom into the light cluster connector X318 Blue/Brown wire. I don't seem to have A19 on the loom that came with the bar? This is on page 7 of the pdf. It does however say that this step does not apply with retrofit cable set A with spare parts
no.: 61 12 0 399 478
No idea why this wouldn't apply to one particular retrofit loom, but perhaps that is the loom that came with my towbar?

I have that wire, also I've just checked the loom I took from the scrap yard car and that came with it too. This is how that wire looks in mine when following the retrofit guide, it just comes out of the towbar loom in the right hand side of the boot, its the same colour and same guage as the rear light wire (blue brown). The wiring came with the scotch locks which I usually hate, but these seem to make a good connection!



On mine, the main struggle was the plastic interior trims and clips, especially around the bonnet release. Also for me the instructions were not correct, I think I had left hand drive instructions, I think the fusebox must be on opposite side on LHD cars? Let me know if you want me to take any photos of that other loom I have if it helps. I still haven't got round to coding on mine but when i do i'll extract all TRC files

[Scoff123]

Thanks James you're a star. OK so that was what I was expecting to have to do with the scotch lock connection, however i have the loom that the retrofit instructions say doesn't use this connection



Apparently i need to check whether the 49HR signal is present on the Blue/Brown cable on the standard wiring harness. Not sure what that means, so will have to look at some wiring diagrams and see what that cable normally does - possibly indicators...

I found the trims ok to remove, but had done them all previously when installing my rear view camera so had a good idea of that to do there.

I know exactly what you mean about the left hand/right hand car things and the instructions - it says to do the CAN wire connections around the fuse box etc first, as if they should be on the drivers side, then feed the loom through and do the FRM and CAS connections. I just worked the other way around and done the CAS and FRM ones in the drivers footwell first.
I did try to connect to the wrong yellow/black cable on the 51 pin connector on the FRM at first, as the instructions seemed to indicate it was the lower of the 2 black 51 pin connectors! Ended up snapping off one of the metal connectors as i withdrew it from the grey cover as it wouldnt come out, and it is well and truly stuck in there, so i've had to remove all of the other wires from it and order a replacement cover from BWW!!





So just the passenger side left to do now, as i've fed the remainder of the loom behind the dash over to that side. Didn't loose too much blood considering but my hands have a few war wounds!

Trace files would be great, not sure what modules get any 'trailer/tow hitch' settings as a result of VO coding the option - guessing we need to deault code the PDC module at the very least after doing this.

Good luck and keep us posted on progress - and thanks again for the info and pictures

[Scoff123]

The more I look at the wiring diagrams with pin outs for the trailer module for the pre LCI vs the LCI, I'm starting to wonder if the 2005 loom I have is going to actually work with my 2011 wiring in the car.

The trailer module uses different pinouts on the pre LCI so I don't think this will communicate properly with my footwell module.

James - did you say you have a complete spare LCI retrofit loom and modules? I may have to look at getting this and starting over with the wiring which is annoying as the bumper and bar will need to come back off

[david in germany]

Originally Posted by Scoff123

The more I look at the wiring diagrams with pin outs for the trailer module for the pre LCI vs the LCI, I'm starting to wonder if the 2005 loom I have is going to actually work with my 2011 wiring in the car.

The trailer module uses different pinouts on the pre LCI so I don't think this will communicate properly with my footwell module.

James - did you say you have a complete spare LCI retrofit loom and modules? I may have to look at getting this and starting over with the wiring which is annoying as the bumper and bar will need to come back off

Think yours would be compatible with my 2009?

[Scoff123]

Not if it doesn't work with my 2011 wiring as it will be the same

[jamesfawcett]

Hi I'll take some photos of my loom for you and show you. I only recieved one module in my retrofit kit from BMW, although Im sure in the instructions it mentioned to fit them both! I fitted one from the doner car.

I'll have a hunt round though to see if I have the other anywhere (AHK I think it's called?). I still haven't tackled putting all the trim back in mine and the fusebox is still only back in with two screws, I've a couple of days booked off work this week though to finish it.

I'll post again soon, the doner loom is in my unit but ill be going there to post some ebay stuff tomorrow morning or later today.

[Scoff123]

HI James. It's strange that BMW don't include the towbar activation module (white connector) in the retrofit kit, only the Trailer module (Black connector) - you can't use the hitch without the activation module! Good job you grabbed the one from the donor car.

The Trailer module (called AHM) seems to have been revised a few times over the years. My one is dated 2005 and only has one 12v power feed going to it on pin 1 which is the Red/Violet cable going to fuse 54.
The newer modules have 2 12v power feeds to power trailers with extra lighting requirements. The second feed seems ot be a Red/Yellow cable going to fuse 81?

What I don't understand, is that my AHM trailer module only has one lighting input which is the Centre Brake Light signal form the FRM. It doesn't have any reverse, Fog, Indicator or tail light inputs. Any idea if these signals are fed to the module over the Canbus? I can't see how else the module would know to activate those particular lights.
The newer AHM modules have an input form the FRM for turn signal so not sure why the older ones don't...

The AHK hitch activation module doesn't seem to have changed over the years so I should be ok with my 2005 module.

I've only got one connection on the fusebox left ot make but i've had to order a metal socket contact from BMW as the one that came on my loom was too large to fit in the green 15 pin socket on the back of the fusebox. Then it will be the moment of truth and i can test it all out. My interior is a complete state but i don't want to put any trim back until i know it all works!

[jamesfawcett]

Ahh have you ordered one? I have a few clips and connectors left over from the kit. I also was missing the plastic surround for the button that goes in the boot, good job I grabbed that from the scrap yard too. Its been about 5 months since I bought the kit from them so probably too late to go back to them now, it was open though with some of the parts in a jiffy bag so it could have been a returned kit that might explain it.

I'm not sure what I've connected to because it didn't explain the connections as I went through, I just had a look because another member requested a copy of my PDF. It's uploaded to dropbox is yours the same as this? https://www.dropbox.com/s/reuior3b8g...06047.pdf?dl=0