Well when I say I am new this., I am new new to this. I don't know how to tell what PCM I am on. I just know it came from Chevy 1999 2500 2WD truck, based on the VIN. I did do the "Read Entire PCM" option with PCMHammer to create .bin file. I have numbers on the PCM's sticker as well. I have been researching how I can tell since you posted. I was hoping to return with a more informed answer for you. I know enough to know I need a bin file, and XDF (I have TurnerPro installed), but just wanting to understand it more from the making of the bin and XDF aspect.