Here's the link to the how to build a flash code reader thread:
viewtopic.php?t=60660
Very useful for reading ECC codes.

Here is my homemade version using the obd1 port salvaged from my 94 850 and an obdII splitter:

Once you get the code reader built and working, here is a list of the meanings of the codes:
viewtopic.php?f=1&t=50443&start=20#p380729