Fixed below!

Need assistance with my 2014 F150, 5.0. Last winter I was towing a trailer about 5k pounds when my check engine light and service wrench came on. OBD gave the U0109 code. Throughout this entire process the truck runs PERFECT.... I have replaced the FPCM, cleaned all grounds I can find, had the fuse 27 relocate TSB done, and cannot get the check engine or service light to go out... I threw the towel in and took it to the dealership.... after two hours, at over $100 per hour all they could supply was “we need at least another two hours to diagnose”. So over $400 in labor to just find an issue....? Got to be a better way. So checking a site of real truck guys for help, Thanks in advance!

 

No way for anyone to help remotely over the net. I just looked up all the test procedures to diag that code and there's a boat load of tests they have to run before determining the cause of the concern.

Could be wiring, could be BCM could be etc etc....... Have to put hands/diag equipment on to know for certain.
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Another wards if I want the lights cleared going to have to bite the bullet and spend $3-400 just to find the issue... that’s a bummer....

 

Yeah unless you want to change careers and go to Ford's schools to learn how yourself. We drive multiplexed networks of computer controlled systems that just happen to look like a pickup truck.
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Issue resolved, stripped the wire loom off the FPCM wires, found a semi broken ground and two bare corroded wires, repaired all three, replaced loom and the check engine light and service wrench are off. The wires that were broke were the two smaller wires that run to the BCM. Which makes sense as the code the pops up is something like “lost communication with the fuel pump control module”. Hope this helps anyone who’s truck runs fine but is getting this code along with the check engine and the service wrench.

 

Congrats on resolving it yourself. Makes one wonder how the heck those wires got dinged inside a wire loom. I would have just looked at the loom and if it didn't have any cuts or other damage visible would have assumed nothing wrong with the wiring. Goes to show you don't make assumptions like I would have.

 

I actually read another member had this same issue (https://www.f150forum.com/f38/wrench...9-code-441863/) so I checked it out for myself, Sure enough I had the same issue. The wires have a hard bend in them (see pic below) that must wear the smaller wires over time?

 

And thus proving once again the value of online forums like this one. Thanks.

 

Where is that connector? (so we can check it)

 

i believe thats the fuel pump control module mounted under the truck bed, I wanna say you might need to drop the spare to get to it