looking for help Code-P0231

[Remi19]

P0231- fuel pump secondary circuit low

Rugger311 had the same code and Ford was able to fix it by replacing the inertia switch due to a short. I have also read that the fuel pump wireing hareness may be causing this. i don't want to have the cab pulled. Anyone had this problem?

Replaced fuse for secondary fuel pump and truck ran fine for a few weeks, then same code again. Truck would eventauly fire up but had to clear codes several times before truck would fire. never died once the truck started. always seemed to happen after driving in the heat of the day. Black max tunned and have 126k miles on 2008 job 1 F-250

Any ideas? Thanks

[PowerstrokeTech82787]

Originally Posted by Remi19

P0231- fuel pump secondary circuit low

Rugger311 had the same code and Ford was able to fix it by replacing the inertia switch due to a short. I have also read that the fuel pump wireing hareness may be causing this. i don't want to have the cab pulled. Anyone had this problem?

Replaced fuse for secondary fuel pump and truck ran fine for a few weeks, then same code again. Truck would eventauly fire up but had to clear codes several times before truck would fire. never died once the truck started. always seemed to happen after driving in the heat of the day. Black max tunned and have 126k miles on 2008 job 1 F-250

Any ideas? Thanks

Do what i did for the Vref going to the dpf, find the connector for the secondary fuel pump going from the pcm to the pump and every connector inbetween. Find what pins that wire runs through disconnect the pcm connector and each connector 1 at a time and load test the circuit. If the light bulb is dim-have a short in the harness screw wasting time pulling a cab for that, if i did that and put Mtime in for a wire overlay ford would laugh thier balls off at me. SO just get a spool of wire and splice it in where theres good known current and run that wire to the connector with the wire thats in question. Leave about 4 inches off of the connector for the 2ndary fuel pump. Problem solved.