P1504 Code (IAC circuit problem)
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P1504 Code (IAC circuit problem)
A short history first. 2003 F150 4.6. I replaced the engine a few thousand miles ago and all was well. Just recently it decided that it didn't want to idle and produced a P1504 Code. I replaced the IAC but that did not solve the problem. I can't find any vacuum leaks. The wiring harness to the IAC is showing 11.5v. What else can it be? I need help this is driving me nuts.
Last edited by Muckyp; Nov 10, 2017 at 07:47 PM. Reason: Needs more info
