I have a 411 PCM from a 2002 Escalade. I’ve heard that depending on the time of year it was made, it could have one of two operating systems. The latter OS is more desired and allows for a 4L80e segment swap, which I’d like to do. Is there a way to look at a PCM physically and determine which OS is on it? For example, if I go to a salvage yard and find another PCM, can I tell if it has XYZ OS on it. I do see a calibration number stamped on the current PCM, but did not know if the same calibration can be found on different OS (or in my case, both OS).
I understand I can take my current PCM and change the OS, but that also takes more credits. I have a friend with a salvage yard and connections, so finding a better starting PCM is an option rather than burning through credits. I just need to know how to ID before connecting if possible.