Driving last night, truck shuts off and starts back up, drive a little further shuts off again. Make it home, fires up in the morning, idling getting kids in vehicle and stops running. Have a scangauge II and it throws a P0231 code, in researching this it says its the fuel pump secondary low voltage. Question is, how do i fix this?

220K miles
EGR delete
cat/muf delete

Thanks, Drew

 

Could be the inertia switch
or, wiring between the PCM and HFCM, or the HFCM itself.........could be the non serviceable relay on the circuit board in the cab.
Not one that pops up here often.

 

Thank you navistarnut...
non-serviceable relay what does that mean I can't service it and is the truck a loss? The inertia switch, can I switch it back on/off, I haven't been in an accident or anything that would trip it. Do I look for it to be pressed down or in the up position? Truck will run but it shuts off every now and then. Acts Like its a chaffed wire. How do I diagnose the PCM or HFCM?

 

Thank you navistarnut...
non-serviceable relay what does that mean I can't service it and is the truck a loss? The inertia switch, can I switch it back on/off, I haven't been in an accident or anything that would trip it. Do I look for it to be pressed down or in the up position? Truck will run but it shuts off every now and then. Acts Like its a chaffed wire. How do I diagnose the PCM or HFCM?

 

Do you have 1/4 tank fuel or less? Could be running out of fuel. Happened to me little over a month ago and happened to one of my grandsons this weekend. Neither truck has run out of fuel at that point before. Don’t know if it is buggy gauges or fuel pick up. Haven’t dropped tank on either truck yet. Same symptoms as yours. Would crank back up and run a little while then shut back off.

 

I got the same code in July and I had to replace the fuse panel because the that relay was bad. I hooked up a power light to the fuel pump and a toggle switch with an inline fuse to bypass the relay so when this happened again my scangauge put out that code p0231 I looked at my light and it was out. Flipped the toggle switch on an my truck started up and ran fine ,so it was my relay. I also replaced the FICM with a 53v Bulletproof diesel unit and replaced my fuel pump until I figured out that the relay was my problem.

 

How do I check all of the PCM and HFCM wiring? And how do I know if the HFCM is bad, or the relay? I dont want to start throwing money at stuff when I could've just replaced one thing ya know. I did hit the inertia switch just as a fail safe and still throwing the code, and full tank of fuel and it still shuts off. I don't think its the inertia switch as the truck will start back up right after if shuts off. I understand these switches can go bad or be an intermittent problem. Again just trying to narrow down so I'm not throwing money at stuff.

 

The DTC is for no voltage on the fuel pump monitor circuit.

Visually inspect the wiring to the HFCM and see if there is evidence of a bad connection or chafing.

The fuel pump relay is built into the Central Junction Box, and the fix to a bad one is to replace the CJB under the steering column.

IMO the best bet for troubleshooting that is what scarty111 did.

 

Thanks for the reply's. I went ahead and got a blue spring upgrade kit, cheap enough and an easy safe guard for the injectors. And the panel, its the one under the steering column just to the left? I thought it was the one under the hood? Of course I'll check the PCM and HFCM connections for chaffing and what not prior to ordering a panel. Does anyone have a site to order the panel or is this a junkyard find?

 

I was googling a little and found at rock auto they have a fuel pump opening circuit relay switch, is this what I need? It's not a panel its the actual relay itself, I do know what a relay looks like and its function but Ive been hearing I need to replace the panel? And on rockauto there is no panels for said application only the relays/fuses. Am I missing something?

 

You are seeing a standard relay there, it's used in a lot of different locations.
It's not the relay you need, the relay you need is soldered to the CJB under the dash/steering wheel.

If in fact, after you have confirmed the other things mentioned here, you likely need a new central junction box, I.E. the CJB.
Sucks yes, but there are worse things that can go wrong.

I'm not saying the relay can't be sourced, and re-soldered, but I have yet to read of someone that did.

 

The whole fuse panel (OEM FORD) cost me around $450.00. Trust me I fought with this code for about 4 months until we figured it out and we checked ALL the wiring harnesses. When we hooked it up to the machine it told me I also had poor fuel injection performance so we checked the FICM and the owner before me installed a Swamps ficm as it was written on the inside of it and was suppose to put out 58v and it was on its way out as the voltage was failing.

 

Gotcha thanks guys. I'll look tomorrow around for the wires and check all that. I'm leaning more towards the relay and unfortunately gonna have to get off my wallet. Ill post back in a few days let yall know what I find.

thanks again

 

Is this the proper fuse box I would need? 2006 6.0 mine is an xlt this is for a lariat which I know is the trim, I have power everything windows, doors, seats etc. I think it is but just making sure.

https://www.ebay.ie/itm/2006-FORD-F3...IAAOSwZ4dZMN8L

 

Not sure I would roll the dice on something that might have some differences. Not saying it won't work.
Go here
https://parts.autonationfordwhitebearlake.com/, plug in the VIN and see what you come up with, then you can go to some other websites that have used CJB's with the same part number.

I'm not sure if you can even get a new one anymore.