[aguyandhisdog]

2004 F-350 6.0 CC/LB with 48,000 miles. Engine is almost completely stock, not bulletproofed (sinful, I know).

I'm throwing a P0528 code and my fan is running 100% of the time now. It was intermittent for a couple days but now it's happening all the time. It's only about 30-40 degrees up here so it definitely shouldn't be running at startup.

I'm also getting codes P0611 and P0470 but their are no symptoms for either of those. I'm wondering if there is a voltage issue...?

Not sure how to go about diagnosing this one, I tend to avoid doing electrical issues but I'm thinking this is something relatively small, I just don't know how to chase down this gremlin.

 

[bismic]

What are you using to pull codes? Can you read engine PIDs (parameters) with it?
Can you see your battery voltage when cranking? If so, what is it?

Check the fan clutch electrical harness - sometimes the fan blades damage that wiring. The wiring is supposed to be anchored to the fan stator (which keeps it away from the fan blades), but if it comes loose, the fan blades will damage the wiring.

For the P0470 (just want to confirm it is a 470 and not a 480), it is usually a bad EBP sensor (electrically failed), and the fix is usually replacing it. Check the harness to the EBP sensor and if you don't see anything, you can run with it unplugged for awhile - while you are tracking down the other codes.

P0611 usually means a failed FICM, but if your truck is still starting, I would resolve the other issues first.

 

[aguyandhisdog]

I had a mechanic pull the soft codes and this is what he came up with. I can read some PID's with my bluetooth OBD II reader. I'll go out and check voltage at crank later and report back. I did an oil change last night and unfortunately found out that the last shop to replace the oil filter used the NAPA cap/filter so I'm waiting on a new OEM cap to show up before running the truck again. Hopefully it'll be here tomorrow but shipping is slow up here in Vermont.

Wiring on the fan clutch all looks good. I gave the EBP harness a once-over as well and there's nothing visibly damaged with that either. I'm hesitant to starting throwing parts/money at the EBP if it's not a "real" issue, just something tripped by jumping voltage. Having that P0611 code is what made me think the other two codes might be false since the truck is still running fine (other than the fan) and it's almost certainly not a FICM issue.

Step 1: new oil filter cap
Step 2: check voltage while cranking
Step 3: .......tbd?

 

[bismic]

Definitely don't replace the EBP sensor yet!

My step 3 would be to run w/ the EBP sensor disconnected.
Then my step 4 would be to clear codes, and the see what comes back and if fan behavior changes.

From what you have posted, it seems that the likely issue is a bad fan clutch (assuming good batteries).

Not sure why the P0611 though - maybe others will have some ideas on that.

Definitely get the oil filter and cap corrected. That can cause all kinds of issues - including lack of critical engine lubrication if you get the wrong combination of cap and filter.

 

[Hydro]

Disconnect the fan harness, that will cause the fan to goto the slow position -- if that is true, then need to look for the cause -- either a short or a sensor telling the PCM the engine is hot

 

[aguyandhisdog]

I knew immediately when I saw the tall filter cap that it was wrong so I made sure not to run the truck until I got the right one. Got one on there last night and started her up to test voltage when cranking. Voltage started at around 10 when cranking then jumped up to around 12 immediately after it started and within about 30 seconds was hovering around 13.4. I know 10 is a little low but is that abnormally low or pretty typical? Would that be causing any of the issues I've been seeing?

Some PID's worth noting from running it last night. These are all within the first few minutes of it running, ambient temp's around 40 degrees.
Fan speed sensor: 0 RPM
Manifold Air Temp: -40
Exhaust back Pressure: 6.34 psi
FICM Logic Power: 13.5v
FICM Main Power: 48.5v
ICP Voltage: 1.53v

To be honest I'm not sure how to interpret most of this. It just seemed relevant to the fan running and the three codes I'm getting. To make things more complicated, driving the truck to work this morning the fan wasn't running. Truck acted totally normal.

If I run the truck with the EBP disconnected, what should I be looking for/what is that accomplishing for me?

 

[bismic]

I don't like to see below 10.5 volts when cranking, but 10 isn't going to cause you the problems that you are seeing. It will be a little hard on the FICM, but won't kill it if it only happens occasionally on startup.

The P0470 USUALLY is indicative of a failed EBP sensor. The failure is usually electrical and internal to the sensor. It is possible that when it fails, the v-reference circuit gets messed up. You may still see the P0470 code with it unplugged, but I was interested in whether or not the other codes might be impacted by it. So, that said, I would clear the codes, unplug the EBP sensor, and see what codes return. It should drive just fine with the EBP unplugged.

Manifold air temperature at -40 ..... something wrong there unless you meant 40 (and not -40).

You said the parameters you posted were all within the first few minutes of running. Was the engine actually running in idle when you took that data?

 

[Hydro]

Shorted vRef should throw a bunch of codes -- interesting about the manifold temp, -40 is not right at all -- Fan RPM of 0 would cause the PCM to default to ON to try to cool the engine - Does this truck have the original electronic fan??

 

[aguyandhisdog]

Manifold Temp read at -40 (not 40) and yes, all parameters were taken while idling, within 5 minutes of startup, after not being run for about 24 hours. My exhaust manifolds are VERY rusty so there could easily be a bad sensor down there if that's where the bung is.

@Hydro could you specify what the vRef is?

Makes sense that if fan RPM's are not reading it would cause a default response. That would likely be a bad sensor? Or a complete 1-for-1 on the whole assembly? Not sure if the fan is original, but I will pop the hood after work today. It's 15 years old but only 48,000 miles. The truck is almost completely stock so I'd be surprised if it wasn't original.

 

[aguyandhisdog]

I guess I'm fighting a war on multiple fronts here. One is the fan, which I'm probably going to have to swap a new sensor or fan clutch assy in.

The other is the EBP, which I'm going to pull and see if I can get someone to clear the codes for me. I can't read them on my bluetooth scanner or my little $60 scanner. I'll run it for a couple days and then scan again. If the codes doesn't come back I'll put a new sensor in and call it good. If its still there I'll come crying to the powerstroke.org community again. Is the 6.34 psi reading from the EBP normal at idle? If so, would that suggest that the sensor is good and make everything I just said an exercise in futility?

 

[Hydro]

The tube for the EBP sensor can rust thru towards the manifold and not actually work the sensor -- would be worth the time to look closely for rust holes

The fan speed sensor is built into the rotating electrical assembly on the front of the clutch -- and is not replaceable
The harness likes to get into the fan blades and get chewed up, so take a look there

vRef is the 5.0 volt supply to the fan speed sensor -- it also goes to other sensors on the truck (EBP is one) - you can measure with a volt meter at the EBP sensor connector

Some substitute the older bimetal fan clutch from the 7.3 into the truck -- this is a mistake in my opinion -- the electronic system is superior in maintain engine temperature -- as long as all the sensors are kept working

 

[aguyandhisdog]

vRef is reading at 4.99 at idle (measured from OBD scanner).

Might be a dumb question but is there a way to visibly tell if it's 7.3 fan clutch? Is it wrong to assume that since there is a wiring harness (not just a power source) to the fan that it is the electric 6.0 version and not the mechanic 7.3 clutch?

The more I learn the dumber I feel...

 

[Hydro]

Look on the front of the clutch -- either a bi-metal spring or a rotating electrical connector -- if it has been replaced the engine harness should end at the fan shroud, or be tied back on the main harness

 

[aguyandhisdog]

Update: It's definitely a 6.0 fan clutch. Electrical connections look good and the harness isn't getting chopped by the fan. Is it possible that the thermostat is reading temps wrong? Or would that create a whole host of other problems?

 

[bismic]

As stated in post #4 - one of your issues is highly likely to be a bad fan clutch.

The full version of ForScan on a laptop can probably send signals to the fan clutch to see if it responds. If it doesn't, then they can do that at a dealership. Or you could always just bite the bullet and install a new one even though it isn't 100% conclusive yet (and may never be without the test to send a command to it).

 

[aguyandhisdog]

The dealership up here is pretty horrible with customer service in their parts department. I know from previous experience that they will charge $80/hour for diagnostics. At that point I mind as well just replace the fan clutch for a little bit more. Looking at the fan clutches on rockauto there are options for with/without snow package, reverse rotation, ambulance package, etc... What is the difference in these fan clutches? My truck has the ambulance package and I'd like to understand why the clutch for that might be different than a standard truck.

 

[Hydro]

You have dual alternators? -- not sure the difference in the fan clutch, unless maybe diameter -- or possibly a different diameter water pump pulley

Attached is the diagram and tests for the vistronic fan clutch system -- as mentioned earlier, disconnecting the fan harness will allow the fan to goto low speed -- the clutch could be bad, with the engine off -- try to rotate the fan, should be minimal resistance and no wobble in the bearing

 

[aguyandhisdog]

I have dual alternators. Thanks for that PDF. I'll go through the steps tomorrow once I have some daylight.

 

[bismic]

Pay particular attention to the section that talks about the P0528 code ...

Edit - unfortunately PinPoint Test AH3 seems to be missing from the document (it is the section that talks about P0528 and commanding the fan clutch), but I suspect AH3 would send you to AH4 (or AH5).

 

[aguyandhisdog]

I unplugged the EBP sensor, cleared the codes and drove it to work today. Is it common to hear a pretty heavy fluttering for 1-2 seconds from the turbo when I let off the gas? It is definitely new since unplugging the EBP. I also noticed that the EBP is reading 6.34 even without it plugged in.