2005 F-250 DTC P0046
 

My 2005 Ford F-250 with a 6.0 L , I drive it daily to work and back, I drive an hour each way. It is mostly highway driving. Anyway the other day it started showing a lack of power when starting out and smoking like a freight train, if I stay in the throttle it will clear up and the boost pressure will go up, if I am cruising down the highway the pressure only reads between 1 and 3 psi, I have cleaned the EPB tube and sensor, they were not very dirty at all. I looked in the end of the turbo and it looks clean as well. There is 170K miles on the truck.
Just wondering if there is anything else to do before I try replacing the VGT Solenoid.
Any help would be greatly appreciated.

That code is essentially saying you have an open or short to ground feeding the VGT solenoid, I wouldn't replace the solenoid itself, I'd be going over the wiring harness from the PCM to the VGT solenoid with a fine tooth comb.

It is also possible your turbo is just starting to stick, especially if you are just daily driving this without ever really pulling a large load or hot rodding it and that many miles. The turbo's on these trucks like to be exercised to remain functioning properly. Obviously not everyone can do that, so they find themselves pulling the turbo to clean it more often, not a huge deal really. I'd check over the harness first, see if you can find any place it's been rubbing. If you can't seem to find anything, I'd pull the turbo and give it a cleaning. :tu:

Ok, I will go over the wiring this weekend and see if I can find anything. I do run this truck pretty hard traveling the highway and also pull a 38' travel trailer every couple months. I looked in the end of the Turbo and it doesn't look too bad. Not sure if looking in the end of it would really show anything, This is my first Diesel so Im not real familure with them.
I will let you know what I find. Thanks for the info.

Yeah looking in either end wont tell you much, at least not with the issue you're seeing. That's good that it gets worked out often.

Check over the harness and let us know what you find. If you can't find anything, this is the next step to take IMO: DTS Articles - Turbocharger Reconditioning

Ok, so I checked all the wiring and can't find anything that looks bad or anything.
If the VGT solenoid is bad, will it give the P0046 Fault?

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Ok, so here's the latest, I hope I can explain this, the truck starts and idles just like it always has, doesn't idle rough or anything. What it seems to be doing is loading up on fuel and once I throttle it, it smokes a lot then clears up, boost pressure comes up and it still has plenty of power, it will eventually load back up until I put a load on by accelerating.
The boost pressure will drop to 0 while cruising down highway until I start climbing a grade then it will blow smoke again. I do have an Edge programmer installed, it has been on there for over a year now, I have also changed the programs and that had no effect to the issue I am having.

It's basically the vanes on the turbo are not working correctly. The turbo is shutting down on you driving down the road (thus the black smoke) then when you get into it and get pressure up it spools up again, but sluggishly. I would be easy on it until you get this resolved, as you're creating a ton of backpressure (hard on headgaskets).

What I want you to do now is clean the EPB sensor. I had this EXACT same issue happen, but I had no codes. I started monitoring the EPB sensor readings and it kept going from full MAX to full MIN continuously. Mine ended up being the wire harness going to the EBP sensor was chaffed up pretty good.

Under the hood, find the drivers side exhaust manifold. Tapped into the manifold you'll see a stainless tube, follow the tube up and you'll find the EBP (exhaust back pressure sensor). Remove the sensor and the tube, clean both thoroughly and reinstall, then try driving the truck again. I'd inspect the harness going to the sensor too.

I removed the tube and sensor and checked and cleaned them the other day, there was nothing in the tube, it was pretty clean, I went ahead and sprayed brake cleaner through it and made sure it was clear, the sensor was a little gummed up, I used brake cleaner and a small pick to get it cleaned out. After that there was no difference in the truck. I checked all the wiring this weekend and found nothing bad on it either. I haven't checked the rubber hose yet, I will do that this evening, if nothing there, the next step would be to remove the turbo and clean it, correct?
Also driving in this morning I got more DTC codes that came up P0046, which was the original one that came up, then I also got P0341 and P2262. I'm thinking this is getting over my head and I will have to take the truck in and have it checked.
I really do appriciate all your help so far.

Try this:

https://www.dieselbombers.com/ford-p...2262-code.html


More codes are good, it tells us where to look! You can handle this one, I promise you, you're NOT in over your head despite what you may think. The link for cleaning the turbo is in there too. My guess is your MAP hose may need replacement, other than that I'd clean the turbo.

Would you happen to have a picture of the MAP hose, I think I know what one it is, but I'm not 100% sure.

If you look at the intake manifold, passenger side, the hose comes right off of a barb on the top of the manifold there, can't miss it, it's the only thing going into the intake manifold right there.

Ok, so I pulled the MAP hose off, it had a small split on the one end, I trimmed and put it back on, drove the truck home, no difference really, so I bought new hose and installed it still no difference, so I though I would restore it back to the original program just to make sure it wasn't anything with the Edge programmer, after I restored it to the original program it was really bad, the truck wouldn't hardly climb a hill on the road to my home. The engine was running around 3000 rpms and barely made it up the hill, the Turbo never did build any boost, based on that and what it felt like to me, I am thinking maybe the cat is the problem. I will try bypassing that tomorrow and let you know how it goes.
Again I appreciate all the help. Thanks!!!!!

Does the truck blow any smoke when it's low on power like that and you're hard on the throttle?

It was dark outside at that point, I was trying to see if it was smoking and it didn't
appear to be smoking.

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Ok so tonight I unhooked the exhaust in front of the cat and test drove the truck. No improvements, I set it back to the original program and when driving up the hill the RPM's would go to 3200, I was going 30mph and no boost. I help it on the floor all the way up the hill and it stayed right there, no smoke at all. I then reprogrammed it and it would go as fast as I wanted it to go and build boost pressure up to 28 psi in about 3 seconds or less,it may have kept building psi but I had to get out of it. However when I throttled it hard it poured the smoke for just a second or 2 and cleared up. it acted the same with the exhaust unhooked in front of the cat and hooked up as normal.
Anyway I look forward to hearing your thoughts on what the next move should be.
Thanks for your help!!!

Pull it off and clean it like mike said in his first post. That way that can be resolved and we can move on from there or it might fix the problem. Ton of miles on that turbo. Goodluck :c:

Ok so I pulled the Turbo off over the weekend, cleaned and polished it just like the instructions said to do. The truck seems better as far as the Turbo spooling up, however it is still not right. It is taking a while for it to spool up and still putting out some black smoke for just a few seconds before it really kicks in. I drove it to work today and it seemed to be working ok on the way in, then it was acting up again on the way home.
It is better than what it was before, just seems to be sluggish still when starting out.
What do you think I should do next?

Has the EGR valve been pulled and cleaned? I can't believe I didn't ask this in the first post.

No that I have not done. The truck seems to run ok after it is warmed up also. Is there an instruction on how to clean the EGR?

It's right on top of the intake manifold. Unplug the wire harness, two bolts hold the valve in, just remove it out of the intake manifold and clean it. Remove the o-rings off of it first, go at with carb cleaner (DO NOT use brake cleaner), a small pick and a toothbrush will probably help. Sometimes they're a pain to get out too, you may have to pry on it with a big screwdriver or the sorts.

Thanks Mike, I will clean that and let you know how it goes.
Thanks for all your help so far!!!

No problem, let us know how you make out. There are probably dozens of vids on youtube pertaining to the EGR valve if you need some visual aids too.

Here's a good article on the EGR function: DTS Articles - Diesel EGR

Here's one on cleaning: DTS Articles - EGR Servicing

Those should help!

Ok so I pulled the EGR valve last night and cleaned it using carb cleaner, it didn't apppear to be that bad, I made sure it wasn't stuck or anything. I cleard the DTC's and then drove the truck to work this morning, it is still acting up. It is running better than it has been, but is still loading up or something, the boost pressure comes right up but still putting out a lot of black smoke for a minute and then you can really feel it take off. It does have constant boost pressure driving on the highway now and goes up and down depending on the load being put on it. I checked the DTC's when I got to work this morning and still have the P0046 and agan the P2262 showed up this morning.
The fuel milage is also coming back up, so the truck is running better.
Sorry to be a pain, but what do you think i should try next? Any ideas?
Again thanks for all your help.

At this point, you've tried nearly everything I can think of to rid of that p0046, and the only thing left in my eyes is the VGT solenoid itself. I'd have a tough time swallowing buying a new one... myself I'd probably try and find a known good one on ebay, or a buddy with a 6.0 and swap it around. It's either that or the turbo itself is just past it's prime. Black smoke is telling us it's fueling up but the turbo can't catch up and clean it out. I'd be tempted to try a VGT solenoid now.

Did you ever pull the turbo and clean it? I know I asked, but I don't remember seeing you post that you had done that. If you haven't done that, that's your next step.

Mike, I did pull the Turbo over the weekend and cleaned it. I do have a buddy here at work that has the same truck a year newer than mine, we did pull the MAP sensor off his and tried it on mine a week or so ago. I will talk to him and pull the VGT solenoid off this afternoon and try it on mine, I will let you know this afternoon if it worked or not.
Will let you know how it goes shortly.
Thanks again for all the help!!!

Awesome, definitely try the VGT solenoid swap then and see what happens. Hopefully that's all it is. Not common for them to go out, but it does happen.

Mike, finally getting back around to let you know how it went with the VGT Solenoid, I actually purchased a new one from Ford and no luck. I'm just not convinced it is the Turbo itself, it always has boost, just not as much as it should when I first start driving the truck, after about 15 minutes of driving something will come loose or something and then the Turbo works fine, once it starts working it works just like it should until I park the truck and let it set long enough to cool off, then it will start all over again. Is there anything else you can think of that might stick and then start working once the truck warms up? Maybe it is just that the turbo is shot or sticking. I just want to make sure I have checked everything before I invest in a new one, I would hate to purchase a new turbo and find out it is something else. Should I take it to a dealer and let them check it out first?
I am just looking for your opinion on what you would do next.
P.S. I have cleaned the EBP tube and sensor, pulled and cleaned the EGR, Checked the MAP hose and sensor, pulled and cleaned the Turbo, tried a new VGT solenoid.
The only other thing I can think of is if the piston that is across from the VGT solenoid is sticking, have you ever seen or heard of that happening?
Thanks for you help!!!

The only other thing I can think of is check over the wiring harness with a fine tooth comb, or maybe even try swapping it with your buddies wiring?

I had the EXACT same problem before, where boost would fall to 0 cruising down the road, roll into it and leave a black train for a mile and then finally it would light and go. Mine didn't really throw any codes, but when I started monitoring EPB sensor, it would go from full max value to full min value and just kept bouncing up and down. I knew something was up. Went to pull the sensor to clean it and noticed the wiring had been chaffed right through on two of the three wires. Pulled it apart, sealed them back up, and wha-la... truck ran fine after that.

These 6.0's are really picky with wiring harness'. Sometimes even if they appear ok, they're not. Always nice to have a buddy with a 6.0 to swap parts with.. :w2: