One Owner Just Did What Tesla Couldn't: Upgrade An Older Car To HW4

Tesla has been kicking the HW3 can down the road for nearly two years. One owner got tired of waiting around.

Photo by: Mack Hogan/InsideEVs

Rob Stumpf

By: Rob Stumpf

Aug 18, at 11:47am ET

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A Tesla owner beat the automaker to the punch by retrofitting newer FSD hardware into his older Model 3.
The HW3-equipped car received new cameras and Tesla's newer HW4 computer.
It took very few parts to actually complete, according to the successful modder.

Tesla backed itself into a corner with the hardware baked into its cars. Millions of Teslas sold between 2019 and 2023 were sold with computers that Tesla sold as "capable" of Full Self-Driving. Yet the company later admitted that this simply isn't the case. It claimed that retrofitting those cars with newer hardware would take a series of micro factories.

One owner didn't want to wait for Tesla to build those. Instead, he took on the challenge himself and became the very first person to retrofit Hardware 4 into a Hardware 3-equipped car, all while documenting the process on X.

The owner is Polish Tesla hacker Mike Gapinski. Ultimately, his working Frankenstein car is made from a 2022 Tesla Model 3 and a scavenged Autopilot computer out of a Hardware 4 Model Y.

Mike says that piecing together the parts was "not as bad as it seemed," requiring only the Model Y's computer, some Hardware 4 repeater cameras, and some light ECU hacking. In fact, he mentions the he was even able to reuse the camera's existing coaxial wiring in the car, adapting it to the new Hardware 4 cameras using adapters for the factory FAKRA connectors.

Thankfully, Tesla has a very robust service reference for these types of electrical schematics which makes finding out what connectors to adapt a breeze. Fitting the actual Hardware 4 ECU was also fairly easy, but did require a bit of hope and zipties to make work.

It's easy to see why any Hardware 3 owner would want to take on this type of project (outside of just pure tinkering, that is). Tesla has been dragging its feet on offering any sort of retrofit for nearly two years. This has left owners of HW3-equipped cars with a "Lite" version of FSD, viewed by the community as inferior to what the HW4 counterparts can handle. It has even been suspected of causing Autopilot computers to overheat by stressing the hardware to its limits.

"Honestly Tesla could have done it ages ago and offer a paid upgrade," wrote Mike on X. "If they end up doing it it doesn’t need so much new parts, but you need to replace all the cameras."

What do you think?

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Comments

There are a few tweaks that still need to be made to resolve some of the remaining trouble codes on the car, but Mike notes that it's running and driving at this point. If nothing else, this is a super cool project for anybody to take on.

Hacking together mods on a software-centric car isn't as easy as slapping a new intake onto your gas-powered car—it's all about knowing how to work with the programming, which is a completely different skill than turning wrenches. Both have their place, but in today's modern Software-Defined Vehicle world, seeing that these cars can still be modded is pretty refreshing.