OpenHaldex-S3

Free and truly open source
AWD control for compatible VW and Audi Haldex systems.

WHAT YOU NEED

INSTALL OPENHALDEX

CHECK COMPATIBILITY

Easy to build and install in minutes!

Supports Gen 1, 2, 4, & 5 0CQ VW & Audi Haldex

If you can wire a light switch, you can build this

Lift the rear seat, plug it in, and you’re done

No custom wiring harness. No soldering or coding. No permanent modifications

What it does:

  • Direct control over Haldex AWD behavior
  • Speed, throttle, RPM, or map-based locking
  • Gen 5 0CQ support with MQB decoded CAN signals
  • Live diagnostics and fully decoded CAN logging
  • Web based control panel and online updates over hotspot

Build OpenHaldex-S3 for Under $50

WHAT YOU NEED:

BUILD:

To run OpenHaldex, only 6 connections are required:

  1. 12V + Power (12-24V)
  2. Ground (GND)
  3. Haldex CAN High (CANHA)
  4. Haldex CAN Low (CANLA)
  5. Vehicle CAN High (CANHB)
  6. Vehicle CAN Low (CANLB)

Note: CAN High is Orange/Black, CAN Low is Orange/Brown.
Brake, park brake, and other unused OEM wires should be connected directly together to preserve the original circuit path.

FLASH:

  1. Connect USB to LilyGo T-2CAN
  2. Enter boot mode
    Hold BOOT, press and release RESET, then release BOOT
  3. Click Install below for your desired OpenHaldex variant

Install OpenHaldex

OPENHALDEX-S3:

This is our own custom OpenHaldex version made for LilyGo T-2CAN from SpringfieldVW.com

OpenHaldex-S3 is a more advanced variation packed with settings.

OpenHaldex-S3 screenshots.

V0.9.3-beta

OPENHALDEX-C6:

That’s right. You can also try our port of OpenHaldex-C6 for LilyGo T-2CAN, based on the original Forbes Automotive release

OpenHaldex-C6 is a more user-friendly, consumer level version.

OpenHaldex-C6 port to LilyGo T-2CAN

V3.00.1

OpenHaldex-S3 Setup

  1. Use your phone, tablet, or laptop
  2. Connect to the available OpenHaldex-S3 hotspot
  3. Browse to 192.168.4.1
  4. Configure your “Setup” page
  5. Customize your AWD

OpenHaldex-C6 Setup

  1. Use your phone, tablet, or laptop
  2. Connect to the available OpenHaldex-C6 hotspot
  3. Browse to 192.168.1.1
  4. Configure your “Setup” page
  5. Customize your AWD

OpenHaldex Compatibility

  • Audi A3 S3 8L Quattro 1998-2003
  • Audi TT 8N Quattro 1998-2006
  • VW Bora 2.8 V6 4motion 1998-2004
  • VW Golf 1J Mk4 R32 4Motion 1998-2004
  • VW Sharan 7M Phase 1 Mk1 1998-2007
  • VW New Beetle RSi 1998-2003
  • Skoda Octavia 1U 4×4 Mk1 1998-2004
  • Seat Leon 1M Mk1 Cupra4 1998-2005
  • Seat Alhambra 7M 1998-2007

  • Audi A3 S3 8P Quattro pre 2009 facelift 2004-2008
  • Audi TT/TTS 8J Quattro pre facelift 2007-2009
  • Volkswagen Golf 1K Mk5, R32, 4Motion 2004-2008
  • Volkswagen Passat 3c, 4Motion, Santana, CC 2005-2009
  • Volkswagen Transporter T5 Prefacelift 2003-2009
  • Seat Altea 2007-2010
  • Seat Alhambra 7M 2005 Facelift 2005-2010
  • Skoda Octavia 1Z pre 2009 facelift 2004-2009

  • VW Golf Mk6 5K 4Motion 2008-2012
  • VW Golf R Mk6 5K 2008-2012
  • VW Tiguan B6 2008-2014
  • VW Sharan 7N Mk2 2011-2015
  • VW Passat, CC, B7 2010-2015
  • VW Transporter Late Model T5 Facelift 2009-2015
  • VW Caddy Mk3 2K 2010 Facelift 2010-2015
  • Audi A3 S3 8P Facelift 2009-2012
  • Audi TT / TTS / TTRS, 8J, 2008 Facelift 2008-2012
  • Audi Q3 / RS Q3 2011-2013
  • Seat Altea XL, Freetrack 2010-2015
  • Seat Alhambra 2nd Generation 7N 2011-2013
  • Skoda Yeti Pre 2014 Facelift 2009-2014
  • Skoda Superb B6 Type 3T 2008-2014
  • Skoda Octavia 4×4, Scout, vRS 4×4 1Z Facelift 2009-2014

  • VW Golf Mk7 and Mk7.5 R / 4Motion
  • VW Passat B8 / Arteon 4Motion
  • VW Atlas / Teramont 4Motion
  • VW TIguan
  • VW Sportwagen/Alltrack Golf
  • Audi S3 8V Quattro
  • Audi TT / TTS / TTRS 8S Quattro
  • Audi Q3 F3 Quattro
  • Skoda Octavia 5E 4×4 / Scout
  • Skoda Superb 3V 4×4
  • Skoda Kodiaq 4×4
  • Seat Leon 5F 4Drive / Cupra
  • Seat Ateca 4Drive

  • What is OpenHaldex?
    OpenHaldex is originally a project created by the user ABangingDonk on GitHub and TTForum.co.uk in 2018. It is an AWD controller for Gen 1 Haldex systems for vehicles such as Audi TT and MK4 VW R32. The controller allows the user to increase the amount of lock requested by the rear wheels. In 2025, Forbes Automotive created OpenHaldex-C6 based on the previous Gen 1 project and added Gen 2, 4, and 5 for VAG Haldex vehicles.
  • What is OpenHaldex-S3?
    I created OpenHaldex-S3 based on the OpenHaldex-C6 from Forbes Automotive, which was sold out when I wanted to try it. I ported the code to a LilyGo T-2CAN and started adding features like map mode, CAN debugging, and more. I stayed with the LilyGo for the increased CPU, RAM and storage vs C6.
  • Is OpenHaldex-S3 safe to use?
    OpenHaldex-S3 has been real-road tested for thousands of miles without incident. It installs on the fused OEM Haldex circuit, supports normal vehicle operating voltage (12-24V), and does not modify general CAN traffic or override factory safety systems.
  • Does OpenHaldex-S3 cause fault lights?
    No. Under normal conditions, no faults are set. Note: during aggressive driving, it’s advised to disable Haldex broadcast, which can trigger a traction control warning. This clears after a key cycle.
  • Is the LilyGo T-2CAN ESP32-S3 board suitable for automotive use?
    Yes, for this application. The T-2CAN is a dual-CAN ESP32-S3 board with a 12-24V input stage and has proven stable in real vehicle use. It is designed as a DIY controller built on readily available hardware. Worst case scenario would be the equivalent of unplugging the Haldex module and losing $30.
  • Why should I try OpenHaldex-S3?
    Because it’s free, easy to build, easy to remove, and built on inexpensive off-the-shelf hardware. It gives compatible VW and Audi owners a simple way to try mode or map-based Haldex control without buying a dedicated aftermarket controller first.
  • What if I don’t like OpenHaldex-S3?
    That’s fine. It can be removed by unplugging it, and you still have a LilyGo T-2CAN development board.