I've been doing a lot of research on self-tuning by going through old threads here and other related forums. I came across this thread
that mentions 05+ ECU's report the VIN, CalID and CVN when queried for it with a scan tool. Anyone know where this is stored? The thread mentioned you have to issue a $09 command. I downloaded a couple stock 2006 ROMs from osecuroms.org for comparison, but it doesn't seem to be a reference to a memory location in the ROM from what I could tell by looking quickly with a hex editor.