Swapping the PCM instantly generates the P1400 code, which is also stored in the BCM. If you're just taking the car into the dealer for routine service or if your car is out of warranty, there's no need to do anything but if you have a warranty claim over $2,000 Mopar is going to demand photos, videos and a data dump. At that point Mopar will see the P1400 and will automatically deny your warranty claim. It doesn't matter how friendly you are with a dealer; the dealer is not going to eat your repair bill when Mopar won't pay them. That P1400 stays with the car for life, so re-installing the original PCM is a waste of time. The warranty paperwork is very clear that swapping the PCM, which is considered tampering with the emissions controls, is an instant warranty voider.