I'm in the middle of of a sas on my 98 2wd runner that I'm converting to 4x4. Question is, is there a transmission control module separate from the Ecu or does the ecu control my transmission. I've already picked up a 98 a340 with transfer case on left side but don't have all the wiring for the 4x4 tranny. And is they a separate transmission harness or is that part of the 5vze engine body harness

 

The transmission harness plugs into the ECU. There's only one. The same harness runs through engine and trans. I think I'm being redundant, but you get it.