[s-cars] Check Engine Diagnostic...

[CyberPoet]

Recently acquired 1993 Audi 100S  V6 126K miles:

Well, still trying to track down a paper copy of the Bentley 3-volume
manuals. If anybody has a lead on them, please contact me...

Meanwhile, the check engine light comes on for no discernible reason at
various times (anywhere from 15 minutes to an hour of driving before it
triggers; resets with an engine restart, and the local Audi mechanic
couldn't pull anything from the car's computer after it had been
cleared by a restart at the shop).

Questions for the list for today:

1. Do I need the scan tool or computer equivalent for this model/year
car (93 Audi 100S), or is there a paper-clip/pin-short method to get it
to give me the diagnostic code(s) without it? I'd like to pull the
codes when the check engine light is actively "triggered", and
obviously if I don't have to invest in a scan tool yet, then so much
the better... (OBDC-1? OBDC-2? Etc?) Any illumination on this matter
would be appreciated. If I do need a scan tool, recommendations on
which models various users are using (likes and dislikes) would be
appreciated...

2. Was this car marketed under a different moniker in any market (i.e.
-- is the 100S the same as the A4 for that year, etc?).

Thanks
=-= Marc Glasgow
just getting my feet wet again...