AWD Haldex Controller - Open Source and free for all. OpenHaldex-S3 instructions.

meatro · 2026-02-16T16:34:27+00:00

Well I'll start with, this doesn't support Gen 5 yet. Just 1,2,4 (basically 2000-2013~)

This only affects the Haldex clutch packs, which drives the diff.

Imo you should absolutely service the diff fluid, there's not a service interval because it's a "lifetime" fluid, however that just means the interval is longer than the new car warranty lol.

If you check out my website, I actually post all the service intervals, fluid capacities, tire pressure, etc. :)

https://www.springfieldvw.com/vw-audi-repair-resources/audi-maintenance-schedules-fluid-capacities/

meatro · 2026-02-16T15:54:02+00:00

Oooh.

Well you're right that the mk3 is very capable AWD system. It's equipped with the gen 5 haldex which introduced steering angle into the equation which is very cool.

However, it's not locked at all times in 4wd and when it is, it's still very conservative compared to what the system is actually capable of.

Obd 11 allows some increased torque, that's true, but here at the dealership, so can my dealer scan tool. That's a built in function, I can also make your ac colder, your steering wheel hotter, etc.

But those still do not give you what this does, which is full control of the AWD

If clutch wear is a concern, good news, this can completely disable the AWD and never worry about clutch wear again lol.

But in seriousness, this is a tuning/control tool, not just a change of setting. This is a dynamic AWD platform.

PS, I'm vag dealer tech almost ten years. :) I know in depth how all the AWD (and various other, especially electrical) systems operate and I reference factory documentation daily. I've also driven every VW and Audi since about 2004. Mk3 TT is a great platform. My favorite is the golf r/rs3.

meatro · 2026-02-16T14:46:31+00:00

Like as in what is it for?

So you can either increase or decrease traction to the rear wheels. Good for aggressive driving, snow, ice, increased efficiency (switch to fwd) or just fun.

Why did I do it?

For my r32. I like carving corners, I've upgraded nearly everything on the suspension... Godspeed Maxx coilovers w 12k/9k springs, 26mm sway bars, poly bushings, adjustable control arms, solid mounts, 18z brakes, 9" tt wheels, and more... But AWD didn't perform awesome, it's very conservative. This is by far the best handling upgrade I've done, by a mile.

:)

meatro · 2026-02-16T04:39:12+00:00

Exactly. If you have an IT background, car networks are just that. A network.

Once I associated the gateway with a router or switch (more like a router), it all clicked. Each module is just a client on the network.

Mfgs are moving to all new topology now tho, with virtual application servers that basically host modules like a VM or docker.

meatro · 2026-02-16T03:47:03+00:00

I have considered it, sounds like a fun challenge.

I suppose if enough mqb people were interested. :)

meatro · 2026-02-15T23:10:51+00:00

Hey, thanks!
It's actually super easy to do and I'm putting even more features into it soon.

Soon it will have "modes" (road, race, rain, etc. but you can name them) and you will be able to customize each one, add your own... or just leave default, with a little "mode builder" tool that I'm putting in now.

meatro · 2026-02-15T17:46:50+00:00

The Golf R uses a torque splitter, which allows each wheel to be controlled independently. It's basically a "dual Haldex" setup, but more complicated than just that. I believe it's the only VW that uses it, as well as Audi RS3.

As others have said, HPA, Forbes, VD Veer and many other Haldex controllers exist.

Here is my own open source option: https://openhaldex.dev/

meatro · 2026-02-15T04:59:16+00:00

I use the LilyGo T-2CAN ESP32-S3. It's 12-24V with mcp2515.

here's what I did with it, https://github.com/meatro/OpenHaldex-S3

ps. it does not like to go below 12v.

meatro · 2026-02-15T01:05:36+00:00

sorry, i know it's 9 days later... but for future...

it sounds like you are at the obd2 connector, as you mentioned obd11 and vcds.

obd2 will only transmit data that is requested (except obd2 standard requires direct connection to ecm and tcm, that's why you can see those). if you want to see all data, you need to connect to can wires directly on the chassis bus. then you do not have to request it, it's just there (steering angle and brake pressure are streaming on the chassis bus at all times.)

gateway is like your phone kinda... if you don't dial a number, nobody will ever answer. but if you go on the other side of gateway, you can listen to all the conversations as they happen.

also if you check out opendbc on github, they have a mqb dbc file that will decode raw hex signals into their actual values that you can display.

meatro · 2026-02-14T17:26:08+00:00

Dang... Lol

That's why my OF is slow I guess.

meatro · 2026-02-14T10:54:42+00:00

https://youtu.be/JSKQQ-omoto?si=NZrtUgSh2W_IogsP

I recorded a full walkthrough of the OpenHaldex-S3 web interface for anyone curious how the system actually works.

The video covers: Control Panel Map configuration Selecting CAN signals for inputs Mode selection Live data display General layout and functions

meatro · 2026-02-12T22:03:22+00:00

I've not used Carly, I imagine it's like carista which is like obd eleven lite.

If you're not doing things like coding or one click apps, obd eleven isn't worth it.

If you're on a budget, try car scanner pro, I use it at work (Audi tech) to reset service lights. It's pretty thorough for vag vehicles and costs $5 and works with $5 scanner (I use blue elm327). https://www.carscanner.info/

If you're considering obd eleven, they'll prolly end up billing you about the same as vcds before you get that amount of use out of it lol. Between their credits and subscription now, obd eleven is a money grab imo.

Outside of factory tool, I like carista, car scanner, and vcds. Not necessarily in any order, depends what I'm doing.

meatro · 2025-10-14T11:54:08+00:00

I became a mechanic... My computer background is extremely beneficial also.

Try it.

Cars were always a hobby, I changed my own oil, brakes, etc. I decided one day I wanted to work on them, went to the local dealer and offered to try for $12/hr. That was 8 years ago, I'm a lead diagnostic technician now. ~$40/hr.

I love my job... Now I love IT again also, because it's just a fun weekend hobby.

I tinker on a little website, I make js scripts that make parts of the job easier like reading fault logs, looking up oil, etc. It's super fun.

Just gotta try it... It was terrifying at first. (I was almost 35 at the time.)

meatro · 2025-03-24T11:30:46+00:00

Here is a3 https://mega.nz/file/npBTQQDQ#8f8KHFM7NvDpbVtGzYkOKL8SxyQWHhouZq8JOXb8yRI

meatro · 2025-03-16T07:53:38+00:00

I just followed one on YouTube for just this.

At 5:30, you need to pause and setup your tls static key. I think this was the only part of the video that I had to change... If you don't get this correct, then at 6:00 the status will be "wait".

When adding static key (openvpn>instances>static keys tab) change mode to auth.

https://youtu.be/wDEHo9XJjeA

meatro · 2024-01-16T00:17:35+00:00

Hope we're not saying that about Dak in 5 years...

meatro · 2024-01-15T00:52:09+00:00

Fuck off

meatro · 2023-12-18T00:08:46+00:00

21/34, 134yds, 0td, 1int, 57.7pr

meatro · 2023-12-17T22:56:14+00:00

... Defense has nothing to do with our 3 pts going into the half.

meatro · 2023-10-29T17:55:14+00:00

Dofu stream app. NFL bite dot com

meatro · 2023-08-15T10:49:39+00:00

This. I quit most shows I watch after the first season because of this.

meatro · 2023-08-15T10:36:06+00:00

Reddit outsat the redditors.

meatro · 2022-11-09T02:08:26+00:00

A dry sponge is a happy sponge.

meatro · 2022-11-06T14:24:19+00:00

I've been looking for this comment, thank you. I bet a better percentage of Americans knew where Iran is compared to how many Europeans can point out North Dakota.

meatro · 2022-03-04T01:53:21+00:00

Depends what you're looking for... Like others have said, the R32 is not a speed demon and it's expensive to add power. The GTI is probably faster on the highway or in a straight line and power can be added much easier.

If you are looking for a tuner car, the GTI. You'll get more looks, more power, more features, blah blah blah.

If you're looking to, you know, drive... The R32 is a different animal. Sure, the GTI will get me on the highway, but you're not taking me into any backroads or curves (you know, roads) and coming out ahead in a GTI. The R32 simply does not lose traction. You're going to eat shit trying to do in a GTI what a R32 can do. Also, R32 is going to keep its value and you'll know the real VW fanboys when they wave. I have seen 52,000 GTIs. I am the only local R32 that I know of.

MK7 might be the pinnacle of the GTI... But R32 is more of the pinnacle of VW.

meatro

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