Look for a company called B&B Electronics. They have a module that connects
a PC to your car diagnostics.

----------
> From: Gerry Cox <gcox@DEK.COM>
> To: PICLIST@MITVMA.MIT.EDU
> Subject: OBD II (CAN based automotive diagnostics)
> Date: Wednesday, May 20, 1998 6:18 AM
>
> I would like to make a tool for scanning the OBD II (On Board Diagnostics
2)
> system in my cars engine management unit.  I believe the system is CAN
based
> and that the protocols are standard but don't seem to be able to find
much
> about it  on the web. Could someone please point me to information about
how
> to do this, ideally with a PC or with a PIC microcontroller? Is there a
> published Spec available?
>
> Thanks,
> Gerry Cox