ECM PINOUT IAC HI/LO | Electrical Mods | Hayabusa Owners Group May 20, 2021Hey everyone! I am nearing completion of my wiring of the Holley HP. I am trying to figure out which side of the IAC is Lo and which side is HI. All 4 wires go to the PCM on the wiring diagram so no help there. I can tell there is continuity between blu/red & yellow as well as wht/blu & brown.. Twitpic Dear Twitpic Community - thank you for all the wonderful photos you have taken over the years. We have now placed Twitpic in an archived state. My Verizon Log In, Sign in to your Verizon Wireless or "Remember me" stores your User ID on this computer. You should not use this feature on public computers. The Tacoma Towing Bible | Tacoma World Dec 02, 2007You route the output signal from the controller back to the trailer brake pin (pin 2, bottom left) in a 7-way round plug. Then you just splice the input signal wire into the brake switch wire. You’ll need a wiring diagram of your truck for this, as I do not know which color wire that is off-hand.