IGBT driver /FAULT = desat output is open collector type and output of all six driver is connected parallel to one signal and on IGBT module there is pull-up to 5v. Same applies to /UVLO signal.
Now looking at your pinmap these pins are not "5V", but instead will read 5V because of pull-ups. Here what I have found:
pin 4 = /FAULT
pin 6 = /UVLO
I'm planning of doing the same modification and move to OI control. Would it be possible for you to share parameters you currently use with this inverter&motor setup?