I know I bounce around with the updates quite a bit but I can't help it. I have an active mind and when inspiration strikes, I just have to go with the flow.
I had a few minutes to myself this morning so I opened up a couple of the spreadsheets of CAN data I've collected from my van and I started to do some digging. Using a handy online hexadecimal converter, I converted my VIN # and searched for the result. Sure enough, I found the pattern!!! I discovered that PID 4FF broadcasts the VIN over the bus in three chunks. (It also broadcasts another packet that is split into two chunks but I haven't figured out what that is yet.)
As an example of what this all looks like, here is a cargo van VIN I found online:
Here is what that VIN looks like in hexadecimal format:
31 46 42 4e 45 33 42 4c 58 44 44 41 31 30 31 35 31
In the stream of CAN data, this is what the VIN looks like to our van's network of modules:
4FF 30 31 46 42 4e 45 0
4FF 31 33 42 4c 58 44 44
4FF 32 41 31 30 31 35 31
So what does this mean exactly? Well, for one it means that I've crossed the line from casual geek to full-on nerd because I got pretty excited when I figured this out...I may have let out an "F yeah!"...possibly a snort as well...definitely had to push my glasses back up on my face. Second, deciphering all of these PIDs will allow me to do things (like remove the PCM after the swap or spoof other modules) with a simple microcontroller. I have an Arduino on the way with the parts for connecting to the CAN bus. I can program this little microcontroller to broadcast CAN packets... or maybe even convert a CAN packet from one manufacturer's format to another format.
Is this interesting to you guys? Do you want to see more of the CAN PID deciphering or is it a little too geeky? I love to write so I don't mind sharing my experiences with this stuff but if you'd rather see transfer case rebuilds and transmission adapters and fabrication of motor mounts, I'll stick to just that. I don't want to bore people to death with hex conversions and bus traffic. Haha!