We have 2 of the E444 units. One had a steering fault so I replaced the steering sensor with another and now the steering is good but have a 06A31 error and it won't drive. I pulled the COMBIAC1 unit out of another E444 and swapped them over and the smaller steering controller one but now both of the units have the error.

I have a complete parts E444 I car swap parts out of but it's hard to work out where to start.

I'm not tech but I like to fix (or break) things myself. Any guidance would be great.