Quote:
Originally Posted by gasmeter
I would design my own carrier board / processor / add can interface etc.
One question though, the can bus connections on the obd2 port, are they the same as the K bus and are the active in terms of listening for packets on the K bus and sending messages back ?
Ideally i'd like to start without tapping into the bus but simply using the diagnostics port as the hardware will be on and off like a yo-yo for along time .
Either way I am following this thread with keen interest.
Peter
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No, OBDII is on its own bus.
I dont think that the steering wheel is even on the same bus as this discussion is referencing (KCAN). I think the standard multifunction is interfaced into the SZL (Steering column switch cluster) through the coil spring assembly. The SZL is on FCAN and PTCAN. The PTCAN is of note as I believe this is how the Performance wheel gets its data.
The signals from the buttons to the SZL are a simple construct of a voltage divider (to generate the button pressed) and voltage comparators (to "decode"). Now eventually the process, in some form, is pushed onto the KCAN by the JBE to the RAD/CCC. Its going to take some effort to localize these messages as it may not be a one-to-one packet event.
Here's a breakdown of the process
Path:
1) MF buttons -> SZL; --------------- No bus. Just simple voltage divider/comparator
2) SZL -> JBE; ----------------------- FCAN or PTCAN (probably FCAN)
3) JBE -> RAD/CCC; ------------------ KCAN