So, my next thing to do it's to try to change the NEC IC from the spare ECU to the main one. If I mess this up, I need to buy a new ECU anyway.
I saw 2 useful videos on YT -
THIS and
THIS
I need to know for sure if the NEC IC is responsible for canbus failure and not to change it for no purpose.
I'm talking about
THIS ONE
If someone has a better photo with it, I would be grateful!