AFS Control Module Replacement - Incorrect Coding

[gmarvin]

Hello all,

Somewhat over one year ago, I hit a car from behind in my 2017 Golf GTI. The right headlight casing broke, so, to avoid dealership fees, I ended up ordering a used headlight assembly on ebay. I had no experience working with cars under the hood, so a friend kindly invited me to his garage and walked me through the process of replacing the assembly.

So far so good, and this allowed me to pass state inspection. But two problems remained, which I put off dealing with until very recently: since the crash, (1) the right DRL wasn't working, and (2) the AFS cornering lights were not working. Both issues were obviously turning up errors every time I started the car.

Now, when we were replacing the headlight assembly about a year ago, my friend had pointed out that there were signs of corrosion on the DRL control module. Recently, I found in myself the energy to try to tackle this myself. I ordered the control module, took off my bumper (a first for me), and replaced it. Error #1 gone!

The AFS error remained. Seeing signs of corrosion on that module as well, and encouraged by my success, I decided to order a replacement and do the same thing. Now, the original part has the number 5N0941329. But since this part has been superseded by 4H0941329 and is very significantly more expensive than the latter, I decided to order 4H0941329 for about $40 instead of 5N0941329. I was partly encouraged to do this by the following video, which I had to have auto-translated into English captions: . The video seems to indicate that the two parts are interchangeable. On the basis of the video and a couple days' worth of obsessive forum searchings, I expected I would need to recode the module, so when I replaced it and nothing happened, I promptly ordered myself an Obdeleven. I re-entered the long coding of the AFS module and did the Basic Settings 2-step procedure (basic headlamp setting, acknowledge basic setting). Unfortunately, I kept getting errors for incorrect coding. They followed the control module when I swapped it to the left and then back to the right. At the end of the day I cannot get the following two error codes to leave:

U101400 - Control module incorrectly coded
static

C1082F1 - Right headlamp power output stage
Incorrect coding
static

I think I'm at a dead end.

I've attached a history log. Be warned: it has a billion scans and rescans from this morning as I took the modules in and out and tried to get magic to happen. Is the new control module just not going to work? Am I going to need to order the expensive, superseded one? I'd really appreciate some help.

Marvin

Attachments:

OBDeleven_Log.txt (73.78 KB)

[dv52 (Australia)]

 . Marvin: Hi.

First, a deduction - which may be completely incorrect (because I reading between the lines of your words)! I assume from your name and from your writing style that this is a "Yankee" car- maybe? 

The reason for identifying the country is because North America Region (NAR) model mk7s are built differently to the rest of the world cars (no surprise - there!! ). These differences mean that NAR model cars are "alien" to those of us that live in the rest of the world (no offense intended) - so, this caveat is an important qualifier for the rest of my words below!

OK - let's start by clearing-up my confusion (probably because i find American accents difficult to understand- it's my problem, it's NOT yours!)

Your post is mostly about what you call the "AFS module" - I assume that you actual mean the Right Headlamp Power Output Stage and NOT the 55 Headlight Regulation module. I seek this clarifcation because you say in your post "I re-entered the long coding of the AFS module". If I'm correct, that's NOT the way that the Headlight Power Output Stage is programmed - read later reply!

Now, I have tried to understand your video insert - but I find the language infinitely more confusing than American accents (again, no offense) . In any event - I'm ALWAYS uneasy when non-official sources claim that modules with different part/software numbers are equivalent. If you have translated the video into "American-speak" and if this is the video's claim - then it's my strong suspicion is that someone might be telling porkies!!

This is what is meant to happen when replacing a Power Output Stage. It starts with the 55 Headlight Regulation module which you can think-about as being the "master" module for the Power Output Stage modules (and for the DRL modules that you replaced) - which are "slave modules". Following the successful retrofit of a new Power Output Stage and if there are NO compatibility problems, the  55 Headlight Regulation module will automatically program the long-code string in the slave module!

Clearly this didn't happen with this car!!

I suggest that your read THIS - because the story appears to be EXACTLY the same as this car - note the part numbers of the left/right Power Output Stage modules and note the fix!!

Don

[gmarvin]

Hi Don, thank you for responding so soon! Haha, your deduction is correct: it is indeed a North American model.

Yes, the module in question that I replaced was the slave module that I believe is called the Power Output Stage module. Forgive my loose jargon; I'm a newbie. What I did was to re-enter the long code of the master module (Headlight Regulation Module 55) with OBDeleven, since I thought that would prompt it to automatically re-code its slave modules.

One thing I want to make sure I understand: Are you saying that the master module would probably have done the re-coding for a compatible Power Output Stage module on its own, without any prompting via OBDeleven?

In any case, the forum thread you linked (thanks for digging it up!) is certainly a strong indication that I should be looking for a 5N0941329. If I decide to order this unit in the near future, I'll provide an update.

As a follow-up question in case I don't do so, do you know if it is possible to make any coding adjustment that would remove that annoying AFS startup error without my actually correcting the fault?

Marvin

[dv52 (Australia)]

Jul 7, 2024 1:05:18 GMT gmarvin said:

One thing I want to make sure I understand: Are you saying that the master module would probably have done the re-coding for a compatible Power Output Stage module on its own, without any prompting via OBDeleven?

I can't say with certainty - sometimes the master module will behave properly and auto re-code the slave module. A lot depends on what other errors appear from the modules after the retrofit  - generally the guiding principle is that the less errors, the more likely the auto re-code will happen without the need for intervention!

Jul 7, 2024 1:05:18 GMT gmarvin said:

As a follow-up question in case I don't do so, do you know if it is possible to make any coding adjustment that would remove that annoying AFS startup error without my actually correcting the fault?

hmm....... not likely!! I guess you could tell the BCM that this car doesn't have an AFS facility - but then the AFS equipment would get cranky because it was being ignored! Other than that - maybe changing the headlights to a more basic version of HID - but again, this is likely more complex (and more expensive) that just replacing the Power Output Stage.

[gmarvin]

Thanks, I appreciate the help

In the meantime while I try to find a reasonably priced Power Output Stage, if anyone has any insight on what's going on in that Russian-language video I that I linked in my original post, I'd be curious to hear it!

Edit: I've attached pictures of my old, faulty module. When I'm looking for a replacement, does it strictly need to match the number 5N0.941.329 on the sticker, or is it enough if it matches the number 746-960-00 AE that is visible in the black plastic above it and the number 746-959-00 AC that is visible in the black plastic on the other side? I don't know what these other numbers mean.

[gmarvin]

Courtesy update: I ordered a used OEM 5N0.941.329 on ebay for a relatively decent price. When I installed it, the problem disappeared entirely; no coding or anything else was necessary.

Thanks again Don!

Marvin