ok so yes I am new to the tunning side and this style of a swap.
I bought a 2008 Silverado with no motor and bad trans (no reverse or some crap). So I bought a 6.0l with a 6l90 from a 2015 van with next to nothing for mileage. TCM will not talk due to the gen difference, the newer tranny has two more wires than the old one. I have the ECU from the truck and the van it runs great but limp mode only. what is my best course of action, harness and computer swap or just use the older trans valve body with its older TCM?
Thanks in advance any info is helpful.
ps, I do not have the BCM of the van either so I will need to marry the new ECU to it if I swap the harness and ECU out for the 2015 model. (correct?)