2006 f250, 6.0, 4x4, AT
Ok, I took my truck to murray state this weekend, which is about a 100 mile drive. Whole way there I got 18 mpg according to the dash on the interstate with the cruise control on at 70mph. On that way back, about 25 miles into the trip, same speed using the cruise contol, The electronic throttle control light popped up.

So, 5 miles down the road I stopped to refuel, looked at the owners manual and says it has gone into limp mode, but I never got the message (fogot what the book said the message was) in the message center on the dash. Started the truck back up, the light is gone.

The only things I notice that are different:
Same speed home using the cruise contol, dash read 23 mpg.
The truck is making lower boost while cruising at a constant speed.

Once I go back in my county wih all the hills I turned off the cruise control and didn't notice a difference in power.

Oh, the truck has seemed difficult to start since I bought it, if that matters.

Any clue what has happened or is happening?
Thanks guys

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well, I'm gonna borrow a scanner tonight to see if it has thrown code.

 

I'll tell you one thing, that display that reads MPG is wrong. Don't trust those things, only way to check mileage is to physically fill it up (to the neck where you can actually see the fuel sitting there), drive it, refill, calculate.

It's possible it went into limp mode for a short time, it will come back out of it on it's own, it's not a Chevy. I've had mine go in once, 2 miles of driving and it was back to normal. Usually does this when boost is held on too long, ie. me sitting at a stop light in 4x4 boosting it up to wax a MKV GTI.

 

yeah, I've never gone by the display, just noticed it the difference and thought it was wierd. I've only checked the milage once and it was around 14 mpg.

Drove it today and noticed the turbo seems quiet. It use to sound like a jet airplane taking off while under acceleration, now the whistle isn't as noticable, thought it was just me but my buddy said the same thing.

 

Well what's the boost gauge saying? No smoke?

 

no smoke, boost (going by the dash gauge) looks like 3 or 4 lbs at cruising speed (55mph on flat road). I got into it and it hit alittle over 15 lbs.

This is my first diesel so I really dont have anything to compare it too. The boy with the 2003 6.0 did't show up to class tonight. I was hoping to see how his sounds.

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before it had much more of a moan to it.

And I just pulled a code:

U1900

Any imput?

 

What are you reading codes with? Probably not a correct code, but maybe. I've seen bullydogs pull codes that come up with a "U" and then my SCT would pull it up as a "P" so I have to ask...

Your boost numbers are very low. If you roll into it you should see high 20's and usually flat footed on stock programming shows around 23-24psi. Your turbo just may need a good cleaning.

How is the truck primarily used and what mods do you have on it? Does the truck idle a lot?

 

It was a farm truck, so yes, It idled alot be for I bought it a few weeks ago. It was mostly this guys daily driver, ocasionally hauled seed or an antihydris tank, but nothing major. It had the oil cooler and egr cooler replaced 3 weeks ago, and the egr valve replaced 20,000 miles ago. It's stock to the bone. The code was checked by what ever the guy at autozone had.

 

Usually trucks that have idled a lot have issues with EGR's and turbo vanes sticking. If you plan on idling it a lot, the high idle switch needs to be wired up.

20k miles on an egr valve is certainly enough time to gum that thing right back up.

U1900 I see as a overfueling issue, but can't seem to find more info than that. From other searching it just says "lost communication with BUS". Not sure where to point you on that just yet.

Me personally, I'd remove the turbo and clean it. Follow the instructions here: Diesel Technician Society It's easy enough anyone with basic wrenching skills can do it. Just plan an afternoon to do it and take your time. Probably a good Saturday project. Nothing hard about it, but doing it a first time an extra set of hands and some beers will help. It's clear you have a turbo issue if you're only maxing at 15psi. Even if you don't, this process wont hurt anything and can only help.

Next, I'd take the EGR valve out, inspect it and clean that too. Again, it wont hurt to do at all. It will give you an idea of how dirty that intake manifold gets and how quick it does.

Lastly, who the heck buys an amarillow for a farm truck!!! Nice!

 

haha, hell, he replaced it with a 2011 lariot f250, Told me it cost him around $75,000.

Thats what I found on the code as well, thats what had me confused. I found a blown fuse (number 20 under the hood). I was told that fuse could have set off the code by Bobcat. I'll replace it and check it tonight.

I'll probly end up cleaning it this weekend if I get a chance. I need to service it and the excursion,and then put a set of airbags on exscurion, so I'll have to see how much time I've got left.

So if I tear it down that far it would proboly be worth it to go on and get the egr delete kit huh.

 

Once the turbo is out, you're probably about 1/2 way in for an EGR delete, but it's the easy half. Next comes the alternator off, the intake manifold out, the up-pipes... your call on that. If you're planning on doing one anyways, probably a good time yea. Plan a FULL day for that project. You will definitely need another set of hands for up-pipe removal/install (if you want it to only last a day and not a couple).

Replace that fuse and I bet that U1900 goes away. It also came up as a BUS communication error when I searched and most of the "fixes" were to check and replace any bad fuses under the hood. You may have just answered your own question there without even knowing it haha.

let us know how you make out.