Ignition swap won't allow car to start.
I have two 2003 Cavaliers. The coupe was in excellent shape but was totaled in an accident. The sedan has a blown motor (among other inferior condition) and received the coupes excellent components.
I have moved virtually every powertrain and suspension component from the coupe to the sedan. The recipient sedan's cluster was scratched so I moved the coupe’s over. I did move the ECM over to the sedan also assuming that it should be paired with the engine/tranny from the swap. The car ran at this point.
The recipient sedan’s ignition cylinder sticks and catches so I moved that over also. At that point it would no longer start. I attempted the 10 minute relearn procedure but it did not work.
So, I put the old ignition lock back in and got it running again.
Today I swapped the BCM from the coupe into the sedan and swapped the ignition locks again and now it won’t start again and the radio says “loc”.
The Theft warning light flashes 3 times then goes constant and all other idiot lights display constant. Cranking the car turns out all cluster lights except Theft and Check engine. The Theft light doesn’t flash for the 10 minute relearn.
What have I done incorrectly?

isn't the theft relearn 20 minutes with key on?...