7 ms·

See all that time the thief spends near the drivers side headlight? The headlights are on the can bus, if you can tap a couple wires in there the cars is yours

See all that time the thief spends near the drivers side headlight? The headlights are on the can bus, if you can tap a couple wires in there the cars is yours.

ddalex 3y ago
I'm very surprised to see that the ignition control is on the slow speed can bus...
- EasyMark 3y ago
  What part of starting a car is fast compared to the canbus? Speed is relative
  - ddalex 3y ago
    There are usually two can buses a car, a slow one and a fast one. The slow one controls the lights, infotaiment, climate, etc, while the fast one controls the ECU, driver assist, all related to driving.
    - aosmith 3y ago
      If you have access to one you generally have access to both.
arjvik 3y ago
Genuine question - why do headlights need to be on the main CAN bus? Could they not be operated from somewhere closer to the ECU by wires that just carry power and maybe some very simple data lines?
- sleepybrett 3y ago
  It may be something as stupid as a wiring harness layout optimization. You can put the headlights controller at the headlights and only run a single set of CAN bus wires (which are probably in that area anyways), haven't played with CAN I assume they are fairly few and fairly thing gauge, through the firewall of the car.
  - maxerickson 3y ago
    CAN is a 2 wire serial bus using differential signaling. So a couple small wires and maybe some shielding.
    - aosmith 3y ago
      It's not about the cost of wire, it's about the cost of software. This is the auto industry version of MCAS. I wish I was joking.
- ndesaulniers 3y ago
  I suspect fancier headlights can pivot based on incline and steering wheel angle.
- EasyMark 3y ago
  It cuts way down on the amount and expense of wiring, copper is expensive. It makes it easier to pocket some more profit.
  - ranger_danger 3y ago
    just wait until wireless CAN comes around
    - EasyMark 3y ago
      I can see fiberoptics, but wireless just wouldn't be reliable. There are too many sources of noise in a car, plus rush hour traffic with dozens (hundreds?) of cars nearby broadcasting on similar frequencies.
- aosmith 3y ago
  A lot of headlights steer with the car, the can bus is a giant network without any authentication.

See all that time the thief spends near the drivers side headlight? The headlights are on the can bus, if you can tap a couple wires in there the cars is yours.

ddalex 3y ago

I'm very surprised to see that the ignition control is on the slow speed can bus...

EasyMark 3y ago
What part of starting a car is fast compared to the canbus? Speed is relative
- ddalex 3y ago
  There are usually two can buses a car, a slow one and a fast one. The slow one controls the lights, infotaiment, climate, etc, while the fast one controls the ECU, driver assist, all related to driving.
  - aosmith 3y ago
    If you have access to one you generally have access to both.

arjvik 3y ago

Genuine question - why do headlights need to be on the main CAN bus? Could they not be operated from somewhere closer to the ECU by wires that just carry power and maybe some very simple data lines?

sleepybrett 3y ago
It may be something as stupid as a wiring harness layout optimization. You can put the headlights controller at the headlights and only run a single set of CAN bus wires (which are probably in that area anyways), haven't played with CAN I assume they are fairly few and fairly thing gauge, through the firewall of the car.
- maxerickson 3y ago
  CAN is a 2 wire serial bus using differential signaling. So a couple small wires and maybe some shielding.
  - aosmith 3y ago
    It's not about the cost of wire, it's about the cost of software. This is the auto industry version of MCAS. I wish I was joking.
ndesaulniers 3y ago
I suspect fancier headlights can pivot based on incline and steering wheel angle.
EasyMark 3y ago
It cuts way down on the amount and expense of wiring, copper is expensive. It makes it easier to pocket some more profit.
- ranger_danger 3y ago
  just wait until wireless CAN comes around
  - EasyMark 3y ago
    I can see fiberoptics, but wireless just wouldn't be reliable. There are too many sources of noise in a car, plus rush hour traffic with dozens (hundreds?) of cars nearby broadcasting on similar frequencies.
aosmith 3y ago
A lot of headlights steer with the car, the can bus is a giant network without any authentication.