is it possible to swop Engine management Unit on my 2002 focus 1.8tdi?

i have been told that my management unit needs to be replaced as this is what is wrong with my car my electric windows work from the drivers door except for the passenger one from the drivers side when i press the button for the passenger window it will go down and when i press it up it still goes down i have changed the switch but still no good ps the passenger side switch (single ) works perfect i can get spares from a friend who is scrapping 2002 focus same as mine