Ask HN: Do custom ROMs exist for electric cars, for example Teslas?

25 j1000 12 9/1/2025, 12:29:37 PM
I always wondered, in age of almost digital cars, is custom ROM a thing? Like root access and custom features?

Comments (12)

TheAceOfHearts · 34m ago
I don't know about electric cars, but for gas powered cars there are open source ECUs [0][1]. There are also tuners that directly modify the car's firmware to improve performance. Finally, you can connect a computer to the CAN bus [2], which allows you to capture and replay commands, as well as craft your own commands. This is how Comma's openpilot [3] works: it connects to the CAN bus and sends commands for all supported functionality.

What kind of features did you have in mind?

[0] https://en.wikipedia.org/wiki/Engine_control_unit

[1] https://rusefi.com/

[2] https://en.wikipedia.org/wiki/CAN_bus

[3] https://comma.ai/openpilot

thrilleratplay · 11m ago
I think I know what you are asking but it is complicated.

For safety, regulator, historical and frankly common sense reasons, a car is not one system. It is a system of system that communicate via a CAN BUS, https://en.wikipedia.org/wiki/CAN_bus. This is still true for electric cars. Can this be hacked? Like everything else, yes.

Can you side load a new ROM like an android device? Not that know of and hope that never becomes a reality because your phone crashing is different than you car crashing (figuratively and literally). Can you enable/disable features? Yes, usually through ECU hacking. On my P3 Volvo, I bought a cheap stripped down Chinese clone of Volvo's diagnostic tool called DiCE. Once the ECU is decrypted, which is done through brute force, you can use something like https://d5t5.com/article/vdash-volvo-diagnostic or P3Tool to change level settings like the theme of LED dash or engine tuning.

You may be interested in https://github.com/jaredthecoder/awesome-vehicle-security#re...

2rsf · 39m ago
Not ROMs but OrBit is a "OrBit is PC software for diagnostics, configuration, and software flashing for newer Volvo and Polestar vehicles".

American Polestars can, for example, enable their adaptive headlights using OrBit.

https://spaycetech.com/

euLh7SM5HDFY · 39m ago
For Audi there exists https://github.com/Mr-MIBonk/M.I.B._More-Incredible-Bash but AFAIK:

a) it is only modification of existing software

b) it only targets Infotainment system

drob518 · 24m ago
There is a lot of potential liability for anyone who creates something that targets anything other than the infotainment system.
joshmn · 43m ago
Mazdas, kind of. https://mazdatweaks.com/

There are of course after market ECU tweaks and parts that, for example, will change your throttle response with a physical piece of hardware—Pedal Commander is a simple example.

j4hdufd8 · 45m ago
Maybe you want https://comma.ai/, founded by geohot who famously made the iOS and PlayStation jailbreaks
merelysounds · 36m ago
This seems not a custom ROM, but a hardware solution (installed on a windshield, with its own camera).
bigmattystyles · 27m ago
Surprised they aren’t all signing their firmware and not loading it if it doesn’t match a fused cert or something.
egirlcatnip · 1h ago
I believe these systems are quite coupled with the hardware itself, making it quite difficult to port any custom ROM or such on them. I am not aware of any projects with the goals of creating an open-source Android ROM for a car. Even Phone ROMs are slowly dying off, with the exceptions of Lineage and GrapheneOS.
mrktf · 44m ago
I believe law environment need to change to make possible digital custom car's ROM. Now everything can be closed in same of safety, security, user convience...
moktonar · 47m ago
Do they exist for any other car? Genuinely interested