Im swapping a manual transmission into a an 03 dodge neon that was an automatic. I have a mechanic who is helping me with the swap. We have just about everything done and he is telling me we need an 03 neon manual transmission ecu as well as the 03 neon manual transmission wiring harness. Do we have to have the wiring harness and is there any interchanges?

Im having problems finding the ecu and harness at any local junkyards.

Thanks