Working on an 09 duramax that had a bad A50 tcm. Got a new unit from gm and realized it was an A40 after opening the box. Now I know you can run the A40 in the trucks with no problem. The issue im having is giving it a calibration flash. I have an A40 read from and earlier LMM and am trying to flash it but when I do im getting a an error $0540: Incompatible operating system, OS mismatch between file: 25941751 and controller 24256580. I've flashed many new blank A50's in the past with no issues at all. Not to sure what I have to do with this A40. Any help would be appreciated