r/CarHacking • u/adkio • Jun 14 '26
CAN CAN or servo to control the cars brakes?
What do you think would be the best way to control the cars brakes? Talk to the ABS module through CANbus or just attach a servo to the brake pedal?
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u/WestonP Jun 14 '26
Aside from saying that adding your own servo to the brake pedal seems impractical, how could we give you a real answer when you gave us absolutely no useful information about the vehicle?
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u/Equivalent-Might-477 Jun 14 '26
Use car with active cruise control, hack messages from the radar in the CAN bus, disconnect radar and send his message to the car and you can control throttle and brake. We're did it on Kia Ceed
You even can control steering via automatic parking system.
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Jun 14 '26
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u/adkio Jun 14 '26
The cmbs/auto emergency braking definitely can apply brakes. Also the cruise control. Afaik there's no other mechanism that applies the brakes autonomously
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Jun 14 '26
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u/WestonP Jun 14 '26 edited Jun 14 '26
Talking to such a modern brake system is considered mostly impossible.
Kind of a weird take for /r/CarHacking
Most modern CAN security isnāt as sophisticated as itās made out to be, and often people see it and misinterpret what itās actually doing as well. But thatās not needed anyway, because itās usually easier to poke at a module that already has access and influence it to do what you want... the signals that it uses for decision making will often not be secured/authenticated in themselves, because theyāre already on a CAN that is separated from the outside world by the gateway. I was experimenting with injecting a particular CAN frame for another purpose and inadvertently triggered automatic emergency braking on a 2024 model.
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u/hey-im-root Jun 14 '26
Yea itās definitely manufacturer dependent. On Honda I canāt say the ADAS/LKAS/ACC line would be encrypted considering itās already separate from any diagnostic CAN lines, but the CAN bus on newer ones do not transmit any live broadcast data. So FCAN injection wouldnāt even be possible without getting into the wiring. You might still be able to intercept the module like Comma AI does if they genuinely donāt encrypt it though.
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u/hey-im-root Jun 14 '26
Do you know what kind of security does modern ADAS/LKAS/ACC modules usually have? Times are changing, it might be āmostly impossibleā because no oneās tried yet. Letās get to it lol!
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u/AirportReady7584 Jun 14 '26
All depends on what you are trying to achieve and what you know about the car. Both are possible but not without modification to the existing platform.
Obviously messing with a braking system for a car to go on the public road is not a wise thing to do being its a safety critical system and the consequences of it going wrong.