It's been a few years, but IIRC correctly you have 2 EEC test switches... CH A Hard/CH B Hard and CH A Soft/Ch B Soft. If you hold the switch in a respective position, and the manual reversion light of an engine lights up, that fault is indicated.
eg. with the EEC test switch selected to CH A soft, if the #1 or #2 manual reversion lights come on, that engine would have a soft failure in channel A... Before start you run through all 4 switch positions to make sure the manual reversion lights stay out, and as such there is no failure.
As for the failure codes...I really have to think... I think they come up on the T5 display when you select the maintenance switches on the side of the center console (below the collective), but only with the engine in idle (off?)...can't guarantee it though.