I replaced the ECM in an 04' Cadillac CTS with an ECM from an 06' Cadillac STS because of a bad injector channel. I licensed both ECM's when I licensed them. I then performed a write entire of the 04' OS and calibration thinking it would also write the correct VIN, wrong. I then spent two more credits to license the bastard OS, VIN. I can make changes to any of the files now but I can't get it to wrote the VIN over to the 04' VIN. I'm going a little crazy because until the VIN is correct, the car won't run and I can't even remove the key from the ignition.