mpc2013

Ok so as some of you may know im working on swapping a nonrevup motor into a rev up car. Its been a pain to say the least. So the nonrevup motor came from a mt 03 350z. Car I just put it in is a 05 g35 mt6. Its in the car, withthe nonrevup harness, but right now its going to the stock revup computer, ecm. Which im assuming wontwork. So I want to put the 03 computer init. Issues im having is the stock revup harness in the infiniy had 2 plugs that went into the passenger compartment under he glove box. 1 to the computer ans 1to a white box. Now the 03 350z harness has 3 plugs, the first 2 r the same or atleast look the same and plug in but he3rd much smaller plug has no where to go... any 03 guys can help me?

3rd plug is a 4 wire plug. Wires are black, black w/white, black, and black w/red