mchuhn

@browniestarmite - same question for you.
What was the total cost for the Controller and Wire Harness?
Would you mind sharing where you sourced the parts?

Thanks.

Dudealicious

The harness I got from: AudiUSAParts.com
I paid $303.60 but it looks like it went up a few bucks

The control module I sourced from eBay Germany. I basically used google translate and messaged a bunch of people if they would ship to the US.
In the end I managed to get one for around $100. I imagine the same process could be used in any number of EU countries. eBay Spain looks like they have a few to choose from. Just make sure they're selling 8K0907383E and not the model ending in A.

browniestarmite

OK, I'm almost done. Hitch installed. Wiring installed. Module installed. Brake controller partially installed. I'll post pictures and lessons learned later.

However, my mechanic and I appear to have completed all the coding, but we are stuck on one step. For the trailer module 69, how do you enable the VCDS to change the WSC, Importer, and Equipment number values? They are greyed out. I know the Importer is the key value. It's currently 123 and needs to change to 444. It looks like until this value is changed that the hint from watdog using the Curt 57004 won't work to clear the error codes. Please help this VCDS neophyte.

browniestarmite

Alright, I used the earlier hint from drück to clear the trailer light warning messages. I disconnected the red connector from the towing module first thing this morning, waited a few hours, reconnected the red connector, and started the car. Magic! No trailer light messages.

So that leaves the question: is it imperative that I change the Importer value in the towing module or probably a few other modules from 123 to 444? If yes, how is that done exactly?

Dudealicious

in 69 did you change RoW (Rest of World) to North America? Once you change that and exit you should be able to enter the values in WSC, Importer and Equipment #'s.

browniestarmite

Thanks for the response. Yes, indeed. We even verified it. Moreover, we changed the value back to RoW and then back to North America to see if the fields would no longer be greyed out. No change.

I suspect this may be due to the periodic Yes/No/Cancel prompts that we saw. These were not mentioned earlier in this thread or the other threads I found on this subject. I do not recall if we saw the prompt when we were updating the Towing Module, but I suspect we did. Anyway, when you select "Yes", it places 12345/123/12345 in the WSC/Importer/Equipment values. As we didn't know what to select and selecting "No" didn't let the changes "take" on some modules, we selected "Yes". Moreover, the "Yes" button was highlighted.

We confirmed using the VCDS that the 7-way connector signals were working as expected. I further confirmed this using a 7-way connector tester. As far as I can see, it may not be necessary to change the Importer value from 123 to 444, but I'm willing to be informed otherwise. I just need to know how to change it when it's greyed out. BTW, we did try Security Access 12233 on the Towing Module in an effort to un-grey out the fields, but that's not the correct code for it.

Dudealicious

If you are terribly concerned everything is working the way it should you could always take your vehicle in to Audi and let them permanently flash the proper codes where as VCDS is technically a temporary solution that Audi could easily overwrite; either intentionally or unintentionally.
I thought about asking what the cost would be at my next (free) DEF fill up.

A6Gary

As a reference, I had our local Audi dealer program the module after I installed the trailer assembly in our 2014 Q5. The dealer cost for coding the trailer model in 2015 was $145 plus tax. I guessing that the dealer charged me ~1.5 hours labor, which included a test drive and clearly the faults.

browniestarmite

Thank you, Dudealicious & A6Gary. As everything works great, I'm going to leave things as is for now.

For everyone's reference, here are the module codings that my mechanic and I applied using VCDS:

01 - Engine > Coding > Long Coding Helper > Byte 6, change from 26 to 36
03 - ABS Brakes > Security Access > Enter code 61378 (see pop-up that appears)
03 - ABS Brakes > Coding > Long Coding Helper > Change Byte 2 from 1D to 9D
09 - Central Elec > Coding > Long Coding Helper > Byte 18, Bit 5, check “Trailer Hitch/Recognition active”
19 - CAN Gateway > Installation List > Check trailer module 69
3C - Lane Change > Coding > Long Coding Helper > Byte 2, Bits 4-7, check "Trailer Installed"
46 - Central Convenience Module > Coding > Long Coding Helper > Byte 12, Bit 5, check “Trailer Control Module Installed”
6C - Backup Camera > Coding > Manually change the value from 1020010 to 1030010
69 - Trailer > Coding > Long Coding Helper > Change from “RoW” to “North America/US” using drop down list

browniestarmite

mchuhn, here is the list of components required, where I obtained them, and the cost:

Aftermarket Hitch

• DrawTite 75940 hitch $169.45 (eTrailer, MO, USA)
• Pollak 7-way connector mounting bracket $7.36 (eTrailer, MO, USA)
• Stainless steel hardware to mount Pollak bracket to hitch $4.19 (Home Depot, IN, USA)

Trailer module and wiring

• Trailer detection control module: 8K0907383E $89.38 (eBay, Italy) + $15 shipping/handling
• Harness: 4L0971124F $301.19 (eBay, Lithuania)
• Bracket for trailer hitch control unit: 8R0907297A $65.54 (Audi Henderson, NV, USA)
• Two M6 nuts and washers for bracket $1.50 (Home Depot, IN, USA)
• Hopkins 40950 $18.54 (eBay, OH, USA)

Brake controller

• Redarc Tow-Pro Liberty brake controller $135.00 (Redarc, NC, USA)
• Redarc Curt wiring harness $19.06 (Redarc, NC, USA)
• Curt 51522 brake controller wiring $12.74 (Amazon, OH, USA)

TOTAL $823.98

In addition, I purchased the following:

• Reese 7031300 Class III Adj. Weight Carrying Ball Mount & 2" Ball $39.99 (eBay, USA)
• Curt 21800 Trailer Hitch Ball Cover $1.48 (Amazon, USA)
• 7-way circuit tester $7.48 (eBay, CA, USA)