Hey there, im in desperate need of figuring out ecm/pcm problems. I own 2000 automatic 4wd truck, a mechanic said the original ecm was bad so he sourced an ecm p/n 3947912(2002?) truck would start and run but rpm would cut out after 5 seconds of run time.(im aware newer years didn’t have a crank sensor). Fast forward i bought a 2000 donor truck with a manual transmission , I removed the ecm/pcm and all wiring harnesses under the hood and swapped them to my truck(one thing i noticed on the donor truck was it has a crank sensor by the starter but nothing was plugged into it and there was no pigtail in the harness) so i swapped all mentioned above into my truck and I’m still having the same rpm issue as well as throwing a code for no crank sensor signal. Do I need to swap the entire fusebox wiring harness and whatever is included on it to get my truck to not try and read the crank sensor signal?