[caboose]

Hi all. I'm still having a hard time getting my truck running properly.

Right now it's running but it feels like it's running on 6 cylinders. Idle is rough and I get a bad vibration when the TC locks up. I have two codes.
- Cylinder 5 power balance fault
- P0232 Fuel Pump Circuit High

The FICM was recently repaired, injector harness was probed and checks out fine and all 8 injectors were just replaced. I did some googling this morning and I have seen that a bad fuel pump might be the culprit? I'd just like to confirm a few things first.

- if my ICP reading as shown by my DP Infinity tuner seems normal would that mean the fuel pump is ok or should I check fuel pressure at the secondary fuel pump on top of the motor? I'm seeing 600ish psi at idle. Higher when driving.

- if it turns out to be a bad primary pump should i replace it with a FASS type system?

- is there a way to test the secondary pump on top of the motor?

- if I'm due for the blue spring update would my symptoms indicate that?

- other things I should check?

Thanks!


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[caboose]

Priced out the filters and blue spring upgrade at a local Canadian Ford dealer.

Ended up just ordering a bunch of stuff from Riffraff Diesel for less than half the price.

Also ordered a mini fuel pressure gauge to mount on the fuel filter housing. I'll get that installed to verify fuel pressure then continue with the troubleshooting.


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[teamroper60]

- if my ICP reading as shown by my DP Infinity tuner seems normal would that mean the fuel pump is ok or should I check fuel pressure at the secondary fuel pump on top of the motor? I'm seeing 600ish psi at idle. Higher when driving.

ICP and fuel pressure are two very different things. ICP is the pressure of you high pressure oil system. There is no fuel pressure sensor from the factory on these trucks and consequently, the only way to test your fuel pressure is with a manual gauge.

Unless you have added one, you don't have a secondary fuel pump on top of your motor (or anywhere else). The stock system has one fuel pump, inside the same housing as your large fuel filter. That small housing on top of the engine only contains the secondary fuel filter and the fuel pressure regulator.

- if it turns out to be a bad primary pump should i replace it with a FASS type system?

That one is your call and your choice. If you are running stock injectors, replacing the stock pump should be sufficient, especially if you do the blue spring mod.

- is there a way to test the secondary pump on top of the motor?

Answered that one above.

- if I'm due for the blue spring update would my symptoms indicate that?

The blue spring mod is probably a good idea but it won't do anything for that P0232 code. That code indicates a short or a stuck relay.

 

[caboose]

ICP and fuel pressure are two very different things. ICP is the pressure of you high pressure oil system. There is no fuel pressure sensor from the factory on these trucks and consequently, the only way to test your fuel pressure is with a manual gauge.

Unless you have added one, you don't have a secondary fuel pump on top of your motor (or anywhere else). The stock system has one fuel pump, inside the same housing as your large fuel filter. That small housing on top of the engine only contains the secondary fuel filter and the fuel pressure regulator.

That one is your call and your choice. If you are running stock injectors, replacing the stock pump should be sufficient, especially if you do the blue spring mod.

Answered that one above.

The blue spring mod is probably a good idea but it won't do anything for that P0232 code. That code indicates a short or a stuck relay.

Great, thanks for the clarification. I'm still somewhat new to diesels so I'm learning quite a bit.

I'll replace the relay under the hood and check for voltage, continuity and shorts in the circuit to the fuel HFCM.

 

[caboose]

Ok, replaced fuel pump relay and cleared the DTC. Pump is getting 12V now and running normally. We'll see if the DTC comes back....

Also replaced fuel filters, did the blue spring update, and installed a pressure gauge on the regulator. I'm seeing 65psi at idle now so I don't think I'm having any problems with low fuel pressure.

Next step is to take the truck into a ford dealer this aft to get them to run an uncompensated power balance test.

 

[ford_doctor]

I'll replace the relay under the hood and check for voltage, continuity and shorts in the circuit to the fuel HFCM.

Ok, replaced fuel pump relay and cleared the DTC. Pump is getting 12V now and running normally. We'll see if the DTC comes back....

Okay, lets back the trolley up!


This is the forum for 6.0L Power Stroke diesel engine and drivetrain in the 2003-Up Super Duties and Excursions - right? The fuel pump relay on all 6.0L F-Series/Excursions is not serviceable. The fuel pump relay is internal to the central junction fuse box. The fuel pump relay cannot be removed or accessed; if the fuel pump relay is determined to be faulty, the central junction fuse box must be replaced. Which is in the dash, not under the hood so this leads me to ask, what relay did you replace?


You should also create a signature that tells us details about your truck that can assist those who want to help you... such as model, model year, engine, transmission and so on. :thumbsup:

 

[caboose]

Okay, lets back the trolley up!


This is the forum for 6.0L Power Stroke diesel engine and drivetrain in the 2003-Up Super Duties and Excursions - right? The fuel pump relay on all 6.0L F-Series/Excursions is not serviceable. The fuel pump relay is internal to the central junction fuse box. The fuel pump relay cannot be removed or accessed; if the fuel pump relay is determined to be faulty, the central junction fuse box must be replaced. Which is in the dash, not under the hood so this leads me to ask, what relay did you replace?


You should also create a signature that tells us details about your truck that can assist those who want to help you... such as model, model year, engine, transmission and so on. :thumbsup:

Perhaps I'm using the wrong terminology.

Relay #302 (or maybe #303, can't recall off the top of my head) is for the HFCM, correct?

Good advice on the signature. Truck is a 2006 F250.


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[ford_doctor]

YOUR 2006 F320 fuel pump is supplied power from fuse F2-40 (20A) in the Central Junction Box in the dash. Power goes directly to the internal fuel pump relay then out through the Inertia Fuel Shutoff Switch then to the fuel pump. Fuse F2-40 is directly fed from the battery feed and is hot at all times. No other relays especially under the hood. The other side of the relay is powered by relay "301" as shown in your owners Guide however it too is in the instrument panel fuse box and supplies power internally to the fuel pump relay. If that relay was bad the truck would power up the PCM and output devices, would not run at all and you could not communicate with it using a scan tool. At this point I am thinking that you either corrected a poor electrical contact somewhere while unplugging and plugging in connectors while testing- OR -you have an intermittent problem and the fuel pump is working... for now.

 

[caboose]

Curious. This pic (found it while googling) illustrates the info I have. Fuse 7 and Relay 302 are the ones I'm referring to.

Can you clarify what relay 302 and fuse 7 are for?

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[caboose]

Relay 301 is for my DRLs. Both relay 301 and 302 are located in the box on the driver's side just forward of the firewall.

Can anyone tell me what fuse 7 and relay 302 are for? Why are they labeled as HFCM?

 

[ford_doctor]

Relay 301 is for my DRLs. Both relay 301 and 302 are located in the box on the driver's side just forward of the firewall.

Can anyone tell me what fuse 7 and relay 302 are for? Why are they labeled as HFCM?

I don't know where you got that goofy picture but it is inaccurately labeled and thus the cause for the confusion. The Fuse and relay you are dealing with here are for the FUEL HEATER, not the fuel pump. It is a dedicated fuse and relay and should have no affect on the fuel pump or any other electrical component or system. While the heater is indeed in the HFCM, the fuse and relay are not accurately labeled in the Owner's guide which was probably the source for the picture labeling. It helps to actually look at the wiring diagrams.

The trolley is now moving again.

If your 2006 truck actually has a fuel heater, it means that your truck is an early build for that model year as the fuel heaters were eliminated on all F-Series 6.0L diesel trucks built after 5/16/2005. If equipped, there will be three harness connections on the HFCM, fuel pump, fuel heater and water in fuel sensor (WIF).

 

[caboose]

I don't know where you got that goofy picture but it is incorrectly labeled and thus the cause for the confusion. The Fuse and relay you are dealing with here are for the FUEL HEATER, not the fuel pump. It is a dedicated fuse and relay and should have no affect on the fuel pump or any other electrical component or system.


If your 2006 truck actually has a fuel heater, it means that your truck is an early build for that model year as the fuel heaters were eliminated on all F-Series 6.0L diesel trucks built after 5/16/2005.

That goofy picture reflects the information that is in my owners manual. That relay and fuse are labeled as "HFCM" and nothing more.

I replaced the relay that Ford chose to label as "HFCM". Sorry for the confusion and thanks for the clarification.


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[ford_doctor]

Yeah, I just went through 2005, 2006 and 2007 wiring diagrams and looked at the owner's guide and came to the same conclusion. Not your fault at all. It's just a case of vague labeling. Now the problem is you still have not identified the cause of DTC P0232. One thing to know here is that with the fuel pump not running, a 6.0L engine will still run and run pretty well in fact. The inectors will draw fuel on their own. This is where the problem with misfiring is likely your root cause - low or negative fuel pressure will damage 6.0L fuel injectors internally. You need to correct the fuel pump/pressure concern first then my guess is that you have an injector or two that are damaged and require replacing. This to me is the likely scenario here and just an educated guess coming from my comfy office desk. If I had your truck in my shop I could tell you for sure.

 

[caboose]

Thanks. There are no competent diesel shops near me so it's been a challenge to get this truck sorted out on my own.

I installed a pressure gauge on the regulator and I had 50psi at idle. After installing the blue spring I have 65psi at idle now.... And it's still running rough.

Next step is injectors. Again.


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