OBD II info

Clive Apps Techno-Logicals 416 510 0020 clive at problem.tantech.com
Thu Jun 4 19:07:01 GMT 1998



just grabbed this from another list

I have the 1996 Ford powertrain manual (PTM), and it has a fair amount
of info on the OBD II stuff including:

- Pinout on the Data Link Connector (DLC).
- Descriptions of the Parameter IDs (PID).
- Description of the communication codes to tell the Diagnostic tools to
perform tests such as the KOER test.
- The Diagnostic Trouble Codes (DTC) for all 96 Fords which may apply to
other years.

What it doesn't have is the communication protocols for talking to the
On Board Computer through the DLC, soooo...I did a little poking around
at the SAE web site and I found the following pertinent docs:

	http://www.sae.org/PRODSERV/stds/J2201.htm - OBD-II interface description
	http://www.sae.org/PRODSERV/stds/J1850.htm - Communications protocol

Each of those docs is $62. Now, I'm not overly motivated to shell out $60

Well, I did a little more surfing and found:

	http://chimera.acs.ttu.edu/~z7d23/research.html

which seems to be a copy of J2201. This mentions that there are 3 possible
communication protocols that a DLC can connect on (two of which are J1850
variants, the third is an ISO communications standard). I also found:

	http://efi332.eng.ohio-state.edu/diy_efi/archive/archive_num_60

which mentions that someone else is working on building a scan tool. Might
want to talk to them.
 
I'll be happy to share the info that is in the PTM with anyone who's willing
to help with a "low cost" scan tool project, but it's 60-odd pages of info,
so faxing it around the internet isn't exactly practical. The DLC pinout is
described in the middle of http://chimera.acs.ttu.edu/~z7d23/research.html

Feel free to forward all or part of this message to anyone else who might help
this project along.

Seth Mleziva <ssm at ici.net>



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