Usely those machines tell you what is wrong… fault code will be shown on status led’s (verical led’s)…
Diagnose/configuration regime it’s a little bit too complicated and you could make more damage than good (I’ve read once one of those and single utility, which I’ve seen, it was how to access configuration in order to set up new boards)…
So, you have there two major help:
– wiring+assembly diagram, program chart too
– fault code displaying (but without fault code guide)