bara002 my skype,
is original fem DEAD?
does your used fem from donor car has key?
so plugg used fem and go for coding and programming and see if ecu is compatible with fem first.
if not compatible than that fem wont work unless you try to flash.
so if used fem has key than use the key to pull isn of fem from bench
and after you write the same isn to dme.
than you will need to do vin change , elv flashing, and other modules.
and everything should work.
but if you dont have working key than you will have to use option 3 on fem/bdc unlock option.and you do rest
after coding the key.
i am not 100% sure if the original key can be re-used but all my original keys i bought i can re-use them.
i did few and all work out well.
but if FEM and DME not compatible the car wont crank after coding the key, but all function of the car will come on.
all the best