freelander 1.8 xei engine replacement

hi there
i have a freelander 1.8 xei.
it has a bottom end problem (the crank)and most cost effective solution is to replace the engine, my question please if you can help is does the ecu need to be replaced with the engine or can we do a straight forward engine swap??
cheers
bruce

the ecu has to go with the engine type.

hi there thanks for the response,i do appreciate it.
just to make sure i have it right.
if i put the same freelander engine back in then the ecu can stay and wont need re mapping or changing? but if i was to source an alternate engine i.e mgf or rover 75 then i would have to replace the ecu at the same time??
thanks alot
bruce