if you are buying a junkyard ecm because your current ecm is tunerlocked then this may or may not be helpful.... As you already know i purchased a ecm off ebay because my chevy ss is tunerlocked so i have been told. So i looked for a used ecm for my year and make and the site pulled up a 13 tahoe with the same service # 12633238 E38. After asking around on the forum i was told that it needed to be reflashed to my vin. I also learned about sps programming that could be done by anyone with a pass thru and a subscription. So i watched some vids on how to do this and learned that the pass thru J2534 i have at work would do the trick. Well not so much!!! The autel MaxiFlash Elite J2534 pass thru device does not work for sps programming. I did install the correct drivers from Maxi PC Suite and then updated to 1.31 version and everything looked good right up until the actual programming. I got a please contact the device manufacturer message. I want to point out that I was running as administrator in windows 10 internet exploder. Also i would like to say that to get to this point took several days. I am not very computer savvy so i may have missed something but i just thought i would share the experience with you all hoping that someone will find it useful and maybe someone who knows what they are doing could point me in the right direction but at this point i plan to give up and take it to the local dealer to see if they can flash it to my vin or just get a new. Any advice is appreciated.