Nicholas Roads

Not sure if I posted in the right place or not. But, this may be a stupid question that I’ve already answered for myself. Either way, I’d like some other input. I have a 2006 Chevy suburban that was having some issues. I ended up changing the pcm to which it fixed the original issues but now I have no power to the 4x4 actuator and the transmission won’t shift. The pcm was bought second hand from a salvage yard, the numbers all matched. But I’m wondering if it’s possible that the pcm came from a 2wd suburban/yukon and not a 4x4. Or would it even matter if it were and should I be looking else where for another problem. Any advice would be very much appreciated.