redfishtd

First we are trying to locate pcm then we will follow wire bundle, still checking hard to get to fuses . I am a f150 guy and have rebuilt ny 05 5.4 l . He has no circuit action on his IAC but 12volts is there ,his egr is not working either , his 02 heaters are not working and it dies right after starting unless he gives it throttle . He has had lots of mods done including exhaust cutouts added . Iac is new third one not anyhelp either . Can't get under it yet too low for us old guys . ,suspect wire bundle damage to pcm or fuse supply problem ??
He is a character 80 years old going back to his teen years now ,good for him . This thing is his baby , he didn't get a manual or anything so its hard to see where 02 heater fuse is , may have to look for broken wires from squrrels or cut during cutout addition . Plus I wonder if 02 wires have contacted exhaust . Can't locate wiring diagrams to help at this point . Yes I know the pcm suppliys a grd to iac ,and egr when needed ,I suppose it controls 02 heaters the same way . Somehow these three are related suddenly iac,egr ,02 heater fail .. We wrote down codes but I'm not at his house now .
Now I wait for help if I can find my way back to here . I am on f150 forums most of the time .We have question areas for different years to divide it up so I haven't piloted this site to see if same . Mine is 05 flyby wire engine but I have 02 sensors . Thanks for any help you can give .

redfishtd

Well we found the problem seems previous owner installed a cheap tuner . The tiny switch on it had fallen near gas pedal and got bumped to in between positions . Put it on stock and everything okay now .