Originally Posted by GSXRliterbikz

Build months were very close. Part numbers matched, HW/SW numbers almost matched. The replacement one was from a sport package 7, so it had steptronic like the X has.
I'm sure theres coding differences that I will need to change to make it function 100%, but it got rid of my TFS.
TCU's are not vin coded like a DME. They can be interchanged as long as they are from the same era. I've done it plenty of times on 7's. When retrofitting a steptronic shifter into a car the easiest thing is to just swap TCU's instead of coding the existing one. Since the X and the 7 share the same trans, it works. I assume using an e39 one would work as well.