[ddalex]

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

[EasyMark]

What part of starting a car is fast compared to the canbus? Speed is relative

[ddalex]

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]

If you have access to one you generally have access to both.