Go Farther With Fēnix Power

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A few words on modifying cars and their software in the US

One of the questions we get asked quite often is about the legality of modifying a car to install our solution.  In the US, aftermarket automotive suppliers have enjoyed more protections than in other countries for many years, however, cars have evolved beyond the standard definitions of those older rules.  For example, many cars have computers and software, and often multiple computers and a variety of software operating them.  Under the old rules and combined with modern software protection rules, where does this leave us?

Well, the simplest way for us to work under the rules as they stood until recently was to make physical changes to the car but to write our software to “play nice” with the car’s software.  This way we’re not actually “hacking” the car’s software, we’re simply emulating what it thinks it’s talking to.  Well that all just changed, and for the better!  The US Copyright Office has just issued it’s updated ruling on software modification and circumvention rules and has specific changes that apply to the automotive world.  Before I get into the details, first a couple of links:

IFIXIT wrote an article summarizing the changes: https://ifixit.org/blog/11951/1201-copyright-final-rule/

The Copyright Office ruling itself: https://www.copyright.gov/1201/2018/

To give a quick example that shows the intent of the ruling, this is from IFIXIT:

The Copyright Office clearly understands the frustration that the repair community is experiencing. In the introduction to their ruling, they include this quote, “[i]t’s my own damn car, I paid for it, I should be able to repair it or have the person of my choice do it for me.”

But more specifically on this topic, here are three quick summaries of how the changes apply to vehicles:

Repair of motorized land vehicles (including tractors) by modifying the software is now legal. Importantly, this includes access to telematic diagnostic data—which was a major point of contention.


Computer programs that are contained in and control the functioning of a lawfully acquired motorized land vehicle such as a personal automobile, commercial vehicle, or mechanized agricultural vehicle, except for programs accessed through a separate subscription service, when circumvention is a necessary step to allow the diagnosis, repair, or lawful modification of a vehicle function, where such circumvention does not constitute a violation of applicable law


Your ability to fix and maintain the products you own is contingent on being able to modify that software. But our tooling hasn’t kept up. For fear of prosecution, farmers and independent mechanics haven’t developed their own software tools to maintain their equipment. Now, they can.

This ruling doesn’t make that tooling available to the public—we’re going to need actual Right to Repair legislation for that. But it does make it legal to make your own tools. And that’s a huge step in the right direction.

So what does all of this mean?  It means we can now write our own software that modifies the software in the LEAF (tools), and it means we can change the software in the LEAF to make it compatible with our solutions (modifying the GOM parameters, circumvent battery swapping protections.)  It also means that others working on aftermarket solutions and software like the folks behind LeafSpy can expand the scope of their products to do more for the consumer.  This is a huge win for the aftermarket solutions business as it applies to Electric Vehicles.  With car manufacturers expanding their software to include hardware validation, encryption, and effectively blocking third-party solutions, those of us working in the aftermarket solutions business can now legally fight back.

-The Fēnix Power Team

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