Can bus Hacking

dts3

I discovered something interesting today. I want to put a little more work into documenting these undocumented PIDs (especially the conversion calculations). Uprev obviously knows all of this already because they can log everything with no problem. My intention was to snoop on the CAN bus while each of these PIDs were being requested one by one. I made a special cable that would allow me to pull a man in the middle on the PID requests. The CAN lines are interrupted which allows me to monitor the bus with my laptop. This is how I was able to read out my ECU ROM.



So I started my CAN logging software on my laptop and started logging in Uprev, hoping to see the PID requests for each parameter one by one. Logging in Uprev was working and I could see correct parameters. I couldn't see it in my CAN bus logging software. I was trying to troubleshoot and noticed that I never connected the CAN lines together. So Uprev does all of their PID request logging outside of the CAN bus lines. I was thinking it's coming in over K-line, but I looked in the FSM and I didn't see K-line being brought out to an OBD pin. We have a K-line BUS but if I remember correctly the FSM says that it's for internal use only, for modules to communicate with each other. Does anyone have any info on this? If I can't see K-line traffic I'm going to have to put a scope on the vendor specific pins, and I REALLY don't want to do that inside of the car.

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