Ok. So i have a 2004 Cadillac CTS, no luxury package or anything hence no GPS, no XM radio. Currently I have an old laptop running Delorme streets USA, and assuming I have a copilot I have a pretty good GPS setup, and that is where the adventure begins.
After finding this site I fell in love with the idea of adding a computer hardwired in the dash. Originally this whole fixation came from just accessing the input for the XM and adding an 1/8" audio cable (which I did) to plug in peripherals and run the audio through the car speakers, but the dealership couldn't get the band programmed.
On a side note, I am an industrial design and mechanical engineering student (dangerous mix); read this as fabrication skills galore, with an idea of what good interface is, but no programming knowledge whatsoever. I've seen the post of the other CTS carputer and that got me thinking about the possibilites.
http://www-personal.umich.edu/~mattbai/
This guy had a good idea, but naturally I'm the guy that wants to go a step further and integrate that whole dash face into the computer setup (no buttons, toggles, switches, etc.) These buttons mostly have nothing to do with the ECU (they all control the radio and whatnot), but the DIC does have the engine info as well as some other nifty info that all has to come from the ECU. There is also the steering wheel controls, and OnStar; I dont know if any of those pipe into the bus but those need to be considered also. So as of now I haven't invested in a scan tool and i would certainly like to, so that I could continue with this ongoing project.
In the end what does this all mean...I, like a few people here, would like to unlonck the mysteries of OBDII, and add to the intricate complexities of my life for fun:nutz:
As far as what I know about OBDII has been mostly due to this forum. I'll look in to the elmscan.
Thanks for the reply.