Ask HN: Do custom ROMs exist for electric cars, for example Teslas?
25j1000129/1/2025, 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)
thrilleratplay · 10m 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.
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.
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 · 44m ago
Maybe you want https://comma.ai/, founded by geohot who famously made the iOS and PlayStation jailbreaks
merelysounds · 35m ago
This seems not a custom ROM, but a hardware solution (installed on a windshield, with its own camera).
bigmattystyles · 26m 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 · 43m 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
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...
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
American Polestars can, for example, enable their adaptive headlights using OrBit.
https://spaycetech.com/
a) it is only modification of existing software
b) it only targets Infotainment system
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.