2020 - Engine shuts off - fueling issue?

[sc85fiero]

If you have corrosion all the way up at that connector you likely have issues further down the harness. You need to pull codes to see if there is any common circuits or connectors affected as a place to start, and then start checking pin fitment, corrosion, water intrusion, etc. on all the related wiring. Unfortunately it can be a tedious process.

-Joe

 

[FordTechOne]

Thanks for the additional info.



Thank you for the additional info. Adding to my list. The truck has seen a lot of salt water/salt flats and despite my best efforts, corrosion exists. I'll check G401 ground to make sure that's still in good shape along with the connector. FPCM connector looks clean but I may need to drop the tank to check the wiring harness running to the fuel pump.

On another note, I've looked on the fordtechservice website for instructions on how C1591 connectors come apart - can't find any details on how to separate this connector which likely means it's simple. The gray latch on the bottom connector in the photo below was opened and after several attempts to disconnect the male to female connectors, I decided to stop and seek some guidance from you helpful guys. Any tips on how to separate this connector successfully?

Incidentally, I started the vehicle before disconnecting C1591. Once I turned off the vehicle, I unlatched the gray locking arm on the female pigtail. When I couldn't get the connectors to separate, I flipped the gray latch back down into its original position. The truck now starts and shuts off immediately. Think this plug could be part of the issue. I didn't damage it, to be clear. I'm just speculating but there could be some corrosion inside.

View attachment 423568

On latch type connectors, especially old/corroded ones, you need to move the latch in small increments and pull apart on the two halves each time. Basically they get stuck and forcing the latch will break it since the halves are stuck.

 

[thatJeepguy]

Thanks for the additional info.



Thank you for the additional info. Adding to my list. The truck has seen a lot of salt water/salt flats and despite my best efforts, corrosion exists. I'll check G401 ground to make sure that's still in good shape along with the connector. FPCM connector looks clean but I may need to drop the tank to check the wiring harness running to the fuel pump.

On another note, I've looked on the fordtechservice website for instructions on how C1591 connectors come apart - can't find any details on how to separate this connector which likely means it's simple. The gray latch on the bottom connector in the photo below was opened and after several attempts to disconnect the male to female connectors, I decided to stop and seek some guidance from you helpful guys. Any tips on how to separate this connector successfully?

Incidentally, I started the vehicle before disconnecting C1591. Once I turned off the vehicle, I unlatched the gray locking arm on the female pigtail. When I couldn't get the connectors to separate, I flipped the gray latch back down into its original position. The truck now starts and shuts off immediately. Think this plug could be part of the issue. I didn't damage it, to be clear. I'm just speculating but there could be some corrosion inside.

View attachment 423568

How much fuel is in the tank when it cuts out?

 

[Ahayslinger]

@1BAD454SSv2

@sc85fiero​

@FordTechOne

Thank you very much for the feedback. Do you guys know if I need to order new pigtails or should I order a new wiring harness?

@thatJeepguy - The engine shutdown doesn't discriminate fuel level. I'm almost certain this is going to be isolated to corrosion within the connectors, grounds, etc. I hope so, at least!

 

[Ahayslinger]

On latch type connectors, especially old/corroded ones, you need to move the latch in small increments and pull apart on the two halves each time. Basically they get stuck and forcing the latch will break it since the halves are stuck.

Great info.

Thanks!

 

[1BAD454SSv2]

@1BAD454SSv2

@sc85fiero​

@FordTechOne

Thank you very much for the feedback. Do you guys know if I need to order new pigtails or should I order a new wiring harness?

Depends on price. If harness was 100 bucks more than pigtails . I would do harness. If there is big difference in price. I would do pigtails . I'm pretty proficient in soldering and heatshrinking. If you don't think you can do a good job and have pay someone. Better off with harness. Lots of variables .

 

[sc85fiero]

Do you guys know if I need to order new pigtails or should I order a new wiring harness?

That very much depends on what you find. If you find some spots with corrosion isolated to one connector or even a section of the connector, usually it can be repaired with a new connector shell and terminal or terminals (ie. a pigtail kit).

If water and corrosion run through a harness it can wick up to the next connectors inline and even creep into further harnesses. A repair is going to be much easier and cheaper than a whole harness but Ive seen enough times where a complete harness or multiple harnesses were necessary to be replaced.

-Joe

 

[ruey220]

Great info.

Thanks!

did you ever find the source of this issue?