Does the ECM taken from the same model Saturn and engine have to be reprogramed?

Its possible to do what your asking you will have to relearn the pass lock so it will start. So why do you think you have a bad ecm?

Most of the ecms I replaced on those cars were because of the scanner not being able to talk to the ecm. What are the codes your getting?The exact code numbers not code descriptions.

Have you tried diagnosing any of those codes to see if it lead to a bad ecm?

Alright with those codes I think your barking up the wrong tree with replacing the ecm.I think you posted another question here today talking about a stall and no start for 30 mins?Lets start with the P0727 engine speed signal fault I have seen a lot of those engines set that code usually caused by a bad crank shaft position sensor especailly with those symptoms. Do you have a multimeter?We can easily check the crankshaft postion sensor when it doesnt start with a quick ohms check.