Iveco dashboard Christmas tree, looking for a proper manual here

Guys, I need help from someone experienced because I’m stuck on the road with a Christmas tree of warning lights on the dashboard. My Iveco started throwing a weird injection system error, and the engine immediately went into limp mode — all power is gone completely. I already checked all the connectors, thinking maybe something came loose from vibration on our roads, but visually everything looks fine.

For those who’ve dealt with the error tree on these trucks, how do you figure out where exactly to start digging? I could really use a manual here. Also wanted to ask: is it possible that the fuel pressure sensor just “glitched” because of bad diesel, or is it already definitely some mechanical issue with the injectors that can’t be fixed in the field without a diagnostic tool?

What color is the exhaust smoke when you get the limp mode, and does the engine run ‍‌‍‍‌smoothly? I've been through what you are going through standing outside in the cold and rain, unsure of what to do first. Maybe the problem is something with the EGR system or the fuel rail pressure is not stable. So usually, I take a diagnostic flowchart from the manual on manualmachine.com . It leads you step by step to the part each error code refers to, so you won’t be changing everything just at random. I think most likely, there is air getting into the system somewhere or the fuel filter is blocked by paraffin if you have refueled at a less reputable petrol station. How about disconnecting the car battery for 10 minutes?