OpenHaldex

The official open-source Haldex controller project by Forbes Automotive

Complete Control Over Your Haldex AWD System

OpenHaldex gives you full control of Haldex AWD systems used across Volkswagen Audi Group (VAG) vehicles, with configurable drive modes, Wi-Fi setup, and OTA firmware updates.

Designed and maintained by Forbes Automotive — enthusiasts, by enthusiasts.

View the OpenHaldex Controller OpenHaldex on GitHub Documentation About

Key Features

Vehicle Compatibility

OpenHaldex supports Generation 1, 2, and 4 Haldex systems used across Volkswagen Audi Group (VAG) vehicles (Gen 5 support is in development). If you’re unsure which generation your car uses, use the compatibility guide below.

View Haldex versions & compatibility

What Is OpenHaldex?

OpenHaldex is a fully open-source Haldex controller project developed and maintained by Forbes Automotive, combining robust hardware and flexible firmware designed to enhance OEM Haldex control logic.

The project was initially started by A Banging Donk just for Generation 1 systems, but we put in the work to reverse engineer the CAN messages and create a controller that supports nearly all generations of Haldex units (Gen 5 still in development).

The project supports Generation 1, 2, and 4 Haldex systems and continues to grow with community collaboration and active development.

The controller reads and adjusts CAN-BUS messages to influence the Haldex unit’s torque bias, allowing configurable drive modes including Stock, FWD, 50/50, 75/25, and custom behaviour directly from your browser, or by adjusting the mode from the button on the controller itself.

Visit the official OpenHaldex GitHub repository to download code, see full documentation, and reference designs.

Looking for more official documentation? Visit openhaldex.com/docs.

Hardware You Can Build or Buy

The official OpenHaldex hardware controller is based on the ESP32-C6 with dual CAN interfaces and Wi-Fi capability. It can be purchased assembled from Forbes Automotive, or built from open-source design files available on GitHub.

Don’t want to build your own?

Frequently Asked Questions

What vehicles is OpenHaldex compatible with?

OpenHaldex supports Generation 1, 2, and 4 Haldex systems used across many Volkswagen Audi Group (VAG) vehicles, including Volkswagen, Audi, SEAT, and Skoda models. Generation 5 support is currently in development.

Is OpenHaldex an official Volkswagen or Audi product?

No. OpenHaldex by Forbes Automotive is an independent, open-source project and is not affiliated with, endorsed by, or sponsored by Volkswagen AG or any of its brands.

What does OpenHaldex do?

OpenHaldex gives you full control over how your Haldex AWD system behaves, allowing you to tailor torque distribution to suit your driving style and use case. Whether you're driving on track, off-road, or cruising long motorway journeys, OpenHaldex lets you choose how and when power is sent to the rear wheels. You can even switch to FWD mode to reduce drivetrain drag and improve fuel economy when AWD isn't needed. All of this is configurable on the fly on your phone, or by pressing the button on the controller itself.

Can I install OpenHaldex myself?

Yes. Anyone can install OpenHaldex themselves using the official documentation and setup guides available on this site and on GitHub. All controllers come shipped with the hardware necessary to install it. Alternatively, you can use the optional harness to make this a plug-and-play installation that takes minutes.

Is OpenHaldex open source?

Yes. All OpenHaldex firmware, documentation, and reference designs are openly available on GitHub. This means if you don't want to purchase one, you can build your own using the open-source design files and firmware.