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Tesla Open CAN Mod

An open-source general-purpose CAN bus modification tool for Tesla vehicles. While FSD enablement was the starting point, the goal is to expose and control everything accessible via CAN — as a fully open project.

Some sellers charge up to 500 EUR for a solution like this. The hardware costs around 20 EUR, and even with labor factored in, a fair price is no more than 50 EUR. This project exists so nobody has to overpay.

What It Does​

This firmware runs on supported microcontroller boards with CAN bus support. It intercepts specific CAN bus messages to enable and configure Full Self-Driving (FSD).

Core Function​

  • Intercepts specific CAN bus messages
  • Re-transmits them onto the vehicle bus

FSD Activation Logic​

  • Listens for Autopilot-related CAN frames
  • Checks if "Traffic Light and Stop Sign Control" is enabled in the Autopilot settings
  • Uses this setting as a trigger for Full Self-Driving (FSD)
  • Adjusts the required bits in the CAN message to activate FSD

Additional Behavior​

  • Reads the follow-distance stalk setting
  • Maps it dynamically to a speed profile
  • Nag suppression — clears the hands-on-wheel nag bit
  • HW4: Approaching Emergency Vehicle Detection
  • HW4: Actually Smart Summon (ASS) without EU restrictions

Prerequisites​

You must have an active FSD package on the vehicle — either purchased or subscribed. This board enables the FSD functionality on the CAN bus level, but the vehicle still needs a valid FSD entitlement from Tesla.

Ban Warning

Any attempt to bypass the purchase or subscription requirement for Full Self-Driving (FSD) will result in a permanent ban from Tesla services. FSD is a premium feature and must be properly purchased or subscribed to.

warning

This project is for testing and educational purposes only. Sending incorrect CAN bus messages to your vehicle can cause unexpected behavior, disable safety-critical systems, or permanently damage electronic components. The CAN bus controls everything from braking and steering to airbags — a malformed message can have serious consequences. If you don't fully understand what you're doing, do not install this on your car.

Next Steps​