Here's a contentious question...

anyone done anything to interface to OBD-II?  Those who know will know,
those who don't, well, it's the mechanism for interrogating the engine
control module (ECM) in new cars.  The ECM is the system that controls
fuel injection, emissions and everything else the engine does, and if it
has a problem it lights up the 'Check Engine' light on your dashboard.
You are then supposed to take the car to a garage and they connect a
device to the socket in your car which displays fault codes to help the
mechanic diagnose the fault (or in many cases the ECM has done all the
diagnosis, and the mechanic simply changes a part).

So, you would have thought that there was plenty of information to be
had about this on the web, but no, a veil of secrecy surrounds the
subject.  So far I have found the SAE standard document references for
the comm. protocol and connector details, which you can get for $62
each, but where are the hobby hackers with their string and sealing wax
interface units and C or assembly language decoding routines written on
their TRS-80?

I could go to the library (remember them?) and get the documents, and I
will, but I would like to know if *anyone* has encountered this topic
before.

PIC content: Of course I want to build an ECM diagnostic display with
our favourite microcontroller...

Andy #2