Hi!
My 110 TD5 is MY -99, but I have changed a used NNN ECU for it, because I have programmed a tuning software into it.
When I first tried the newer ECU, it worked right away, even without programming the Injector codes. Why, I just don´t know, but it did and it also run flawlessly when I was driving it. But for shure, the right method is to program the Injector codes into it by using T4, Nanocom or such, but the swap will work!And of course you should program the new chassis number etc on it, but that doesn´t affect it´s functioning. BUT! if you by a new ECU, it comes empty, so you must get it programmed by someone who has access to T4 and has the latest program updates. You don´t need to buy a new alarms ECU if it´s not dead, and if it is, it doesn´t have to be from the same vehicle, it will work without any programming, at least mine did. Correct me if I´m wrong...
Good Luck, You will get it running!