Yesterday the engine light came on while driving, so I stopped and used my code reader to check the codes. It indicated that code P0299 had occurred TWICE.

I looked up the code number in the book that came with the code reader. It says that this code means "turbo under-boost".

I'm going to take the truck to the dealer to see if they can find out what happened, but I like to be well informed, so:

Has anyone else had this code happen on their 2011 ?

Can anyone explain what might have caused this code and what it means?

Thanks in advance.

Could be a boost tube blown off or leaking or hole in a boost tube or intercooler cracked.

Brian

Thanks Brian for those suggestions. There's nothing obviously detached or damaged based on a visual inspection, so we'll see what the techies find when I take it in later this week.

That sucks man, how many miles do you have on your truck now?

all these problems with the new truck ... did GM drop the ball on quality? Aren't they supposed to be "like a rock" - reliable?

No, they quit with the Like a Rock slogan with the LB7. Its Like a Dump now. ;)

Not that I hate the LB7, but it has cost us tons of cash in repairs in the amount of time we have owned it.

Hey, what's with all the negative stuff ??? The truck is FANTASTIC. It tows like a demon, power and torque to spare, I love it !!!! I'm certainly not writing it off just because it has had a low boost error. Get real guys, and wait for the tech report after I've been to the dealership.

Hey Ted....these days i think there is a lack of QUALITY control, you me and the rest of pay alot lot of money for these trucks for something to go wrong;)

I'm actually very happy with the quality, if that means that the panels all line up nicely, and everything works the way it should - VERY different to the standard for North American vehicles 30 years ago. That having been said, a 2011 vehicle is extremely complex, so I'm actaully surprised that most of them have no problems whatsoever. Prior to the 2011, I owned a 2007.5 and a 2008 and neither had any significant issues, just minor warranty jobs. Same goes for this 2011. I don't want to jump to conclusions about the quality just yet. Maybe I'll change my mind after the Dealership visit, but I'll report back with the results.

I really love mine and I will also say the quality is much better than it was 10-20 years ago. But, as the old saying goes, "If it has tires and t-ts, your going to have problems with them sooner or later":eek:

If it makes anyone feel better, the New Dodges and Fords are throwing just as many or more codes. These computers now tell us if something isn't perfect. In the old day's you didn't know something wasn't right until you heard a noise or lost power ect. So far these 11's are doing very well. there are a lot more of them on the road than we realize. There are some with 35,000 miles or more running around so far with no issues. :D

At about the eleven hundred mile mark our 2011 gave the same code. Called onstar as we were towing on the road. Took it to the dealer the next day and all was fine. I just got some shoulder shrugging at the dealer.

Did the dealer pull the code and do a snapshot? It could just be a gremlin, but they should at least get GM involved to solve the issue. I know it can be annoying.
I bet after John Kenedy get's a chance to play with these LML's he will figure out what's going on. GM would do well to hire him for tuning and tweaking the ECM's. He just seems to take thier stuff and make it better.

OK, just got back from the dealership. When I took the truck in I told them about the engine light coming on, that I had read code P0299, and I expressed concern about the average fuel consumption, which is higher than was the case with my LMM.

Told them that all of the GM sales promotions claimed that the LML would have BETTER mpg, not worse.

Didn't take them much more than half an hour to bring the truck back to me. They told me that GM is aware of this issue and is working on a solution. The tech service rep told me that the fuel consumption and low boost error code appear to be linked in some way.

Anyway, he said not to expect a fix until the first of the year, and he mentioned a PIP4849 which documents the issue.

SO, can anyone get hold of a copy of PIP4849 ???

I got a CEL and onstar said it was a turbo related code also. I am not sure if we are talking about the same one or not. Truck was low on power and ilding a little higher than normal (while smoking from under the hood, which was never fixed by dealer) This paired with the shitty hitch from B&W is really making me pissed off!!

I got the same code yesterday at 900 miles. It was a turbo power Boost problem that GM is aware of. They say they are working on the software that will fix the problem. I should have known there was a problem as my mileage went down prior to code coming up.
:cool:

I just got the low boost code today also Onstar says it will come on if the boost is 7 lbs under normal, mine came on in the parking lot.:confused:

I had the same code again today. This is the third time and I find it curious it only happens when I am pulling the fifthwheel.

Is this CEL actually causing the truck to go into limp mode or is it just throwing a CEL light and nothing else?

Personally I would be surprised if the new trucks didnt have any glitches, that goes for ford, dodge, and gm.

Great I tow all the time and dont need this. For what ever reason mine went off in a parking lot. Since I cleared the code the dealer wont look at it until it throws another code. Do you notice a loss of power like the turbo is under boost? Mine just finished a regen the day before.

I had a P2565 code last week. Turbocharger boost control position sensor circuit high voltage. Truck was low on power and idling.
Took it to the dealer and traced the fault to the ECM.

Replaced the ECM.

Tomorrow I hook the RV up and see how she pulls.

Let us know how it goes first time in my life im hoping for a code so I can take it to the dealer.

The truck does NOT go into limp mode. In my case, the engine light went off again after 48 hrs, before I went to the dealership. Interestingly, and perhaps of some importance, I did not have the code until I was towing my fifth wheel. Anyway, it's not serious enough to cause any problems at this stage so I'm happy to wait for the fix.

My LML has been absolutely flawless, 7500 miles, and it has just handled everything I have thrown at it with ridiculous ease.

Awesome mileage, performance, and everything else.

I do not think it is possible to build a better truck, period.......

Just got the p0299 code yesterday. No limp mode. reset it thinking possibly that it was a fluke and it stayed out untill the same strecth of interstate where it came on before interestingly enough. To me it seems to be someting with sustatined boost. Im at 2200 miles. This is my 3rd issue with this truck. I love GM but if I wanted a $55,000 garage orniment I would have bought a powerstroke.....Starting to wonder if i should have......

Hey Coltxxxxv,

What were the other two issues you have had?

Big time anti freze leak from the coolant jug. Ambient temp gauge didnt work. Currently besides this code there is a nasty sound coming from the LF, not the type writer tick. I've had 3 duramaxs and there is something rattleing around in there. not good. Need less to say I may have to eat my own words and go to Ford if these aren't the end of the problems / or they aren't easy resoloutions. Not the trucks problem but the dealer is also full of morons up here, it was a very shitty deal just ordering and getting the truck with almost none of the PDI even completed on the truck.

OK, just got back from the dealership. When I took the truck in I told them about the engine light coming on, that I had read code P0299, and I expressed concern about the average fuel consumption, which is higher than was the case with my LMM.

Told them that all of the GM sales promotions claimed that the LML would have BETTER mpg, not worse.

Didn't take them much more than half an hour to bring the truck back to me. They told me that GM is aware of this issue and is working on a solution. The tech service rep told me that the fuel consumption and low boost error code appear to be linked in some way.

Anyway, he said not to expect a fix until the first of the year, and he mentioned a PIP4849 which documents the issue.

SO, can anyone get hold of a copy of PIP4849 ???

Here you are Ted:
#PIP4849: Intermittent Turbocharger Engine Undeboost DTC P0299 - (Nov 10, 2010)

Subject: Intermittent Turbocharger Engine Underboost DTC P0299
Models: 2011 Chevrolet Silverado
2011 GMC Sierra
Equipped with the 6.6L Duramax Diesel RPO codes LGH or LML

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

A dealer may encounter a customer concern of low power or the SES light coming on.

Basic diagnosis may reveal a Engine Underboost DTC P0299.

Recommendation/Instructions:

Complete the current SI diagnostic for any DTCs or symptoms found.

If diagnostics are inconclusive and the concern cannot be duplicated, do not attempt repairs.

GM engineering is aware of the concern and the intermittent P0299 is under investigation

This PI will be updated when new information becomes available

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

Thank You ShookMe

Just got the p0299 code yesterday. No limp mode. reset it thinking possibly that it was a fluke and it stayed out untill the same strecth of interstate where it came on before interestingly enough. To me it seems to be someting with sustatined boost. Im at 2200 miles. This is my 3rd issue with this truck. I love GM but if I wanted a $55,000 garage orniment I would have bought a powerstroke.....Starting to wonder if i should have......


X2
I traded in a perfectly fine 2007 LMM for a $51000 head ache
I rely on my truck 7 days a week to haul a livestock trailer which is how I afford to make the payments on it!! WTF

Seems like a bit of an over-reaction to a low turbo boost code that doesn't interfere with the operation of the truck.

I noticed on the Ford forums that some folks over there have also been getting the same code. This MIGHT mean it's a turbo manufacturer's problem.

Well its just the point that I have spent $55,000 for GM to say we will get you a fix eventually, just roll around with your CEL on. BTW the remote start doesn't work with the CEL on. Not huge but Kinda pisses me off on these cold mornings.

I went out today and drove the freeway boost started out jumping around then went to normal. Then hooked up my 14k 5th wheel drove it for around 40 miles 100 miles today total and all is well for now. So guess i will have to wait for the next code. I love this truck and will be glad when this is behind me.

Seems like a bit of an over-reaction to a low turbo boost code that doesn't interfere with the operation of the truck.

I noticed on the Ford forums that some folks over there have also been getting the same code. This MIGHT mean it's a turbo manufacturer's problem.

Not just a code....if feels like I am dragging a battleship bedind me when the CEL comes on anf fuel milage really blows!! Would you feel confident hauling trailer loads of live animals with a truck doing this?

I hope that everyone experiencing the code has taken the time to take the truck to the dealer so that the pressure stays on Engineering to solve the problem.

I would love to if it would throw the code again. Mine seemed to do it right after my regen so will see in another 500 miles

The codes are stored in memory, so even if the CEL has gone out, the dealer can still read the code.

That would have been great but I cleared the code

The DTC still may be in the ECM's history. A tech II would be able to see it if it's still there.

I have had the same problem twice now. First time I had towed 1500 miles(3000 mikes on truck) and got the check engine light and power diminished message. It cleared up before I could get itn to the dealership. Second time, was the other day at 9800 miles and got no message or light, just felt like I lost power. Got it to the dealer this morning and they confirmed the same thing you reported. My problem is, I tow every day and at 8-10 mpg it is killing me in fuel costs.

OK, just got back from the dealership. When I took the truck in I told them about the engine light coming on, that I had read code P0299, and I expressed concern about the average fuel consumption, which is higher than was the case with my LMM.

Told them that all of the GM sales promotions claimed that the LML would have BETTER mpg, not worse.

Didn't take them much more than half an hour to bring the truck back to me. They told me that GM is aware of this issue and is working on a solution. The tech service rep told me that the fuel consumption and low boost error code appear to be linked in some way.

Anyway, he said not to expect a fix until the first of the year, and he mentioned a PIP4849 which documents the issue.

SO, can anyone get hold of a copy of PIP4849 ???

I have to agree, I use my truck for work only and if it can't tow properly it is of no use to me. I have an 06 with 190k on it and the only problem I've had is a wheel bearing at 40K. Remember that the lemon law still applies and if you take it back 3 times with no fix they are required to make it right even if it means buying it back.

Also, when I bought the truck they never told me about the diesel fluid til after I bought the truck and then lied to me about the cost of the fluid. They tole me it was between $2.70 and $4.00 a gal only to find out GM sells it for almost $16.00 a gal. Napa sells it for about $4.25 a gal.

X2
I traded in a perfectly fine 2007 LMM for a $51000 head ache
I rely on my truck 7 days a week to haul a livestock trailer which is how I afford to make the payments on it!! WTF

I was told yesterday that they are aware of the problem and will let me know when they can fix it. As or right now they are working on a solution. This goes for the smoking from under the hood and the turbo code. What kind of truck did I buy?? This is something I would expect when buying a off brand tractor not a GM truck.

The codes are stored in memory, so even if the CEL has gone out, the dealer can still read the code.

Ted, and whoever else is having this code,

If you would like, you can hit me up every so often to check for bulletins and PI's to see if there is any solution to this problem. Save you guys a call to the dealer anyway.

Hope that helps...

Seems like a bit of an over-reaction to a low turbo boost code that doesn't interfere with the operation of the truck.

I noticed on the Ford forums that some folks over there have also been getting the same code. This MIGHT mean it's a turbo manufacturer's problem.

Fords may have had one case here or there but nothing line this. The 6.7l is pretty much trouble free. No smoking under the hood either :)

Fords may have had one case here or there but nothing line this. The 6.7l is pretty much trouble free. No smoking under the hood either :)

Mine has neither a code, or smoke, just brute force, near silence and 20 mpg

IIRC The Ford site has some 6.7 Engines that were replaced......Yeah I guess your right, the 6.7 definitely has less problems the 6.6. That code that doesn't affect performance is terrible! but it's Okay I have nearly 2 minutes at the top of the mountain to reset it before you will even get here in a 6.7! = ]

Thank you Shookme. I'll get in touch every couple of weeks to see what progress has been made.

IIRC The Ford site has some 6.7 Engines that were replaced......Yeah I guess your right, the 6.7 definitely has less problems the 6.6. That code that doesn't affect performance is terrible! but it's Okay I have nearly 2 minutes at the top of the mountain to reset it before you will even get here in a 6.7! = ]

No not some!! There was a storie about a guy that new a guy that new sone one that said a cyl lost comp from a glo plug that broke. They could not supply pic's or nothing.

99% of the 6.7l are flawless

Fords may have had one case here or there but nothing line this. The 6.7l is pretty much trouble free. No smoking under the hood either :)

If you think the 6.7 is trouble free you're not looking.

If you think the 6.7 is trouble free you're not looking.

http://powerstrokenation.com/forums/forumdisplay.php?f=167

I look every day

Powerstroke page---

"probably every 125-150 miles I am getting a regen, that is just a ballpark, I can watch it drop mileage about 1.5-2mpg."

"Well, took my new 2011 out last night and just finished a 350 mile round trip and the truck regen'd 3 times, each regen took place at 100 to 120 mile intervals, regardless of going 55mph or 70mph, and each regen lasted for approximately 10 miles, based on watching the "Instant MPG" gauge. This is consistant with my previous post of the truck regen'ing 3 times inside of 400 miles. Is it possible the 6.7's are programmed to regen at this mileage as a form of "self-maintenance" ?
My only concern with the truck regen'ing this frequently, is "oil dilution".
Does anyone think this would warrant any concern?"

""Truck has been the same non-pulling weakling since it had 3 miles on it. I have to admit that it is a new motor but come on. I have been pulling the same load for the last 3000 miles and no change. I'm going to the dealer to have it checked out.

"Everytime? I watch my gauges very close...but the mileage sucks and the power sucks. What a way to waste 62grand, but the ride is nice and it looks cool."


"9.2 towing and my 06 DMAX will run circles around it. I can't keep up with a stock 04.5 Dodge towing the same weight. Hell and I'm a FORD guy. Oh well can't wait till the end of the month for the upgrade."

"I have almost 8k on mine and about 1k miles ago I started to feel it vibrate when it would go into regen. With in the last 500 miles it will shake your brain lose when it goes into regen. Dropped it off and the dealer called today and said that they put it into manual regen and it vibrated on them. He told me that he does not know what it is and hopefully will have an answer for me in the morning. The only thing that I tow is a 10.5k boat and that is once every other month for about 250 miles. Will keep you up to date as to what Ford says."






http://www.powerstroke.org/forum/6-7-problems-forum/

check out thedieselgarage .com and thedieselstop .com

make sure to look at posts in april, may, june, july, august

Ted,

Just bought 2011 2500 HD with the 6.6 and have had the same problem. Were you hauling something or have weight in the back? I have had it happen twice while hauling. Dealer doesn't know why stated GM is working on it. Truck doesn't even have 2,500 miles on it yet. Strike Two, and it goes back to the dealer tomorrow because the Check Engine light is on again, and the truck will not idle smooth. Jumps between 1,000 to 1,500 RPM while at rest. They had better fix it, or they will own it!


Kyle

Yesterday the engine light came on while driving, so I stopped and used my code reader to check the codes. It indicated that code P0299 had occurred TWICE.

I looked up the code number in the book that came with the code reader. It says that this code means "turbo under-boost".

I'm going to take the truck to the dealer to see if they can find out what happened, but I like to be well informed, so:

Has anyone else had this code happen on their 2011 ?

Can anyone explain what might have caused this code and what it means?

Thanks in advance.

Yes, both times I got the code I was hauling my fifth wheel trailer. I'll bet GM Engineering is burning the midnight oil on this one. It could be related to the exhaust brake being turned on (was yours turned on when the CEL came on?) or towing load or ??? Interesting that the just released pickuptrucks.com real world runoff between the Ford and GM never experienced the code with maximum load and exhaust brake on.

Powerstroke page---

"probably every 125-150 miles I am getting a regen, that is just a ballpark, I can watch it drop mileage about 1.5-2mpg."

"Well, took my new 2011 out last night and just finished a 350 mile round trip and the truck regen'd 3 times, each regen took place at 100 to 120 mile intervals, regardless of going 55mph or 70mph, and each regen lasted for approximately 10 miles, based on watching the "Instant MPG" gauge. This is consistant with my previous post of the truck regen'ing 3 times inside of 400 miles. Is it possible the 6.7's are programmed to regen at this mileage as a form of "self-maintenance" ?
My only concern with the truck regen'ing this frequently, is "oil dilution".
Does anyone think this would warrant any concern?"

""Truck has been the same non-pulling weakling since it had 3 miles on it. I have to admit that it is a new motor but come on. I have been pulling the same load for the last 3000 miles and no change. I'm going to the dealer to have it checked out.

"Everytime? I watch my gauges very close...but the mileage sucks and the power sucks. What a way to waste 62grand, but the ride is nice and it looks cool."


"9.2 towing and my 06 DMAX will run circles around it. I can't keep up with a stock 04.5 Dodge towing the same weight. Hell and I'm a FORD guy. Oh well can't wait till the end of the month for the upgrade."

"I have almost 8k on mine and about 1k miles ago I started to feel it vibrate when it would go into regen. With in the last 500 miles it will shake your brain lose when it goes into regen. Dropped it off and the dealer called today and said that they put it into manual regen and it vibrated on them. He told me that he does not know what it is and hopefully will have an answer for me in the morning. The only thing that I tow is a 10.5k boat and that is once every other month for about 250 miles. Will keep you up to date as to what Ford says."






http://www.powerstroke.org/forum/6-7-problems-forum/


http://www.youtube.com/watch?v=QG8sq6aCbYs

Oil dilution can NOT occur on the 2011s during regeneration because the fuel for regeneration is no longer injected into the engine exhaust stroke, as it was for the 2007.5 thru 2010s. In the 2011, a completely separate injector sends fuel directly into the exhaust stream, so it has no impact on oil dilution.

Not got much into the 2011 yet so there is an injector for fuel and one for the DEF?
Where is the point the fuel is injected?
Any pics of this setup?
Thanks for any info.

Brian

There is a full set of injectors for the engine, and a separate single injector reserved specifically for regeneration. I can't give you the exact position, but it is in the manifold or downpipe just outside of the engine. There is a service bulletin indirectly related to this injector because of a problematic exhaust pipe connection on some trucks which allows diesel fuel to leak to the outside of the pipe. This in turn causes smoke from under the hood during regeneration.

Well, I got the P0299 at approx 330miles this morning (light had been on a few miles before I decided to snap the pic):

http://i162.photobucket.com/albums/t252/tjZ06/IMG00033-20101125-0642.jpg

Like some others I had a regen yesterday, at only about 120miles total on the truck. That seems really early to me, but I guess that's a question for another thread. I called OnStar and they did the scan, and gave me the line about the light indicating an issue with the "turbo charger or intake system." I asked for the specific code, and they did actually provide it, it was of course P0299. I then asked if this was the under-boost code (since I had recalled this thread, but couldn't remember the code number) so they transferred me to a technician who was able to confirm it was indeed the under-boost code.

The truck didn't seem to drive any different, however I am still taking it very easy on the truck so I wasn't really calling on the power. I guess it did feel like I was having to use a lot more throttle than I'd expect... but I had heard a lot of LML owners say that and most attributed it to the tune. I reset the average mileage when I picked up the truck, and I ended up today at 17.0mpg with 400miles. I did a fair amount of in-town and stop and go driving, but also some freeway stretches (though I was trying my best to avoid constant speed/rpm for break-in).

http://i162.photobucket.com/albums/t252/tjZ06/IMG00036-20101125-0807.jpg

-TJ

No not some!! There was a storie about a guy that new a guy that new sone one that said a cyl lost comp from a glo plug that broke. They could not supply pic's or nothing.

99% of the 6.7l are flawless


I work with a guy that has a new 2011 Powerstroke. He wants me to drive it to Northern Wisc. burn it then drive over it with the D6 then bury it. He has bad luck since day 1. Barely got off the lot died would not restart, glow plug issue, then to find out it burned the tip off and fell in the cylinder took out the piston. New motor a few weeks later, turbo issues,electrical issues, any of the new trucks can have any issue but man i told him to go get a GMC, now he is wishing he did.

Update: I drove home from my folks' place today and it def felt like I was down on power. Going up a the Sunol Grade with an empty truck (and no trailer) it seemed like the truck was working just to drag itself up the hill. Just the other day it wanted to rip up the grade. I really worry about the truck not running right (perhaps way too much fuel since the boost is down) while it's still breaking in. :(

-TJ

Another update, the light went out last night (right about 500mi now) so I got on the throttle a bit and the truck really picked up. I'm still going to have the dealer scan it and record the incident even if it doesn't come back.

-TJ

I must say that I have also felt concerned that the truck is consuming too much fuel from time to time. The mpg drops down dramatically for a few days, to maybe 11.5 mpg and then recovers to 14.5 mpg over the next few days, but it happens too often for it to be due to regenerations, especially as regen is supposed to happen less often with the 2011s.

In addition, the exhaust occasionally starts making more of a deep throated "chugging" noise at idle, kind of hard to explain, but again not what I would expect to be associated with regenerations based on my 2007 and 2008.

When I took the truck to the dealership to report the code, I mentioned the poor fuel economy, and the rep said that poor fuel economy is known to be linked to this problem code.

It's obviously turning out to be a challenge for the engineers, but it's starting to look like they have a real problem to resolve. Let's hope it's all in the software and not the turbocharger itself.

I must say that I have also felt concerned that the truck is consuming too much fuel from time to time. The mpg drops down dramatically for a few days, to maybe 11.5 mpg and then recovers to 14.5 mpg over the next few days, but it happens too often for it to be due to regenerations, especially as regen is supposed to happen less often with the 2011s.

In addition, the exhaust occasionally starts making more of a deep throated "chugging" noise at idle, kind of hard to explain, but again not what I would expect to be associated with regenerations based on my 2007 and 2008.

When I took the truck to the dealership to report the code, I mentioned the poor fuel economy, and the rep said that poor fuel economy is known to be linked to this problem code.

It's obviously turning out to be a challenge for the engineers, but it's starting to look like they have a real problem to resolve. Let's hope it's all in the software and not the turbocharger itself.

Are those MPG numbers you listed towing? I did a bunch more city driving and I'm still at 16.5 MPG. I have a 2500 Crew, Regular Bed. I guess if you're a 3500 Crew, Long Bed, DRW you might be a bit heavier... but that still seems like a huge difference. Are you resetting your average MPG a lot to approximate an instant reading? I reset mine when I picked up the truck and have not touched it since (~400miles since then, it had ~98 miles when I got it because it was a dealer trade - I met the old gentlemen who picked it up before I approved, haha).

-TJ

Those are the numbers I'm presently getting, NOT towing, in Ft Myers, Florida, where it is nice and flat.

After we arrived here for the winter about 3 weeks ago I reset the mpg, which was then sitting at an appalling 8.7 mpg after the roughly 5,100 mile towing trip from BC to FL. (My 07 and 08 both averaged around 11 mpg over their towing lives with the same 16,500 lb fifth wheel).

Since resetting when we arrived here, the mpg has fluctuated per my earlier post, (The mpg drops down dramatically for a few days, to maybe 11.5 mpg and then recovers to 14.5 mpg over the next few days), very disappointing, but based only on about 400 miles of travel.

I have a 3500 SRW standard bed.

This is a great thread, thanks to all for keeping everyone informed. I am ready to order a 3500 swr denali (the dually with my trailer would put me over the 26001 lb limit & need a different DL), but i will wait until there has been a fix for this problem. I don't care how few trucks have it, if it is out there, it will find me, thanks again for all that are having to deal with this & keeping the rest of us informed!!!!

No new news from GM yet...

This is a great thread, thanks to all for keeping everyone informed. I am ready to order a 3500 swr denali (the dually with my trailer would put me over the 26001 lb limit & need a different DL), but i will wait until there has been a fix for this problem. I don't care how few trucks have it, if it is out there, it will find me, thanks again for all that are having to deal with this & keeping the rest of us informed!!!!

With the Holiday incentives I don't know if it's really worth waiting. Depending on if you're paying cash or financing etc. there are a lot of good deals to be had. I paid well under invoice, still got a small ($1k) rebate, and got 0% for 60 mo. It's a small issue, GM will fix it, and I'd much rather have to go through a little PITA to get it fixed (if it comes back again on mine) than pay some bank a few thousand dollars over the life of a loan vs. the 0% I got. Just my $0.02 though.

-TJ

got the code AGAIN... Would any of you guys consider hauling a trailer load of cattle from CT to Oklahoma?with a truck acting like this. sucks that a payed 50k+ for this truck and i am reluctant to take it on a long haul

my wife is having the same problem with her rig. Light came on for the second time in 8k miles, loss of power and lot more fuel consumed. This rig needs to haul horses from NY to FL in two weeks, always something!!!

after I got the code again for the second time, I made sure I brought the truck to the dealer to have the code cleared (even tho onstar told me it was the same code) I want to have every issue (especialy return trips to the dealer for the same problem) with this truck documented (incase this is just the tip of the ice berg) I am keeping all the slips from every trip this thing makes back for service.

The upside of my last visit is that the previously lazy service tech did a turbo vane test to make sure there was not really a legit turbo problem. He didnt want to take for granted that everyone gets this code for no reason wich I thought was a good idea. The tech also called GM TAC twice and instead of being told this time "we are aware of the problem and we are working on it, we will let you know when we get it figured out" thyey gave an answer i was a little happier with. They said they expect to have a fix out in 2 weeks. Time will tell.....as for my dealer they are getting easier to work with as they realize my problems with this truck are legit.

I work with a guy that has a new 2011 Powerstroke. He wants me to drive it to Northern Wisc. burn it then drive over it with the D6 then bury it. He has bad luck since day 1. Barely got off the lot died would not restart, glow plug issue, then to find out it burned the tip off and fell in the cylinder took out the piston. New motor a few weeks later, turbo issues,electrical issues, any of the new trucks can have any issue but man i told him to go get a GMC, now he is wishing he did.

I know a guy that has a cousin who's sister said she talked to a guy at a gas station that had problems with their 2011 Ford. They clearly ALL suck. HAH.

Every time I read this forum you guys crack me up. You have problems and start comparing them to issues you found on Ford forums, and blow them all out of porportion.

The 6.7's haven't had any real WIDESPREAD problems like this. The regens work great with no power loss, just a slight tone change from the engine bay. Regens happen at very consistent intervals and last right around 10 minutes _every time_. If I'm in a lot of city traffic i can regen at 150 miles. If I'm driving mostly highway it'll regen at about 300-350 miles. This seems very consistent with what everyone is seeing. It's FAR better than my 6.4l which seemed to have NO correleation between regens and driving habits and the power loss was nearly unbearable. On the 6.7 if I didn't see the regen notification or instant milage meter drop i'd never know it was in regen mode unless I was idling with the windows down next to a brick wall so I can hear the subtle change in engine noise(I first noticed it in a drive through and thought something was wrong).

Anyhow the issue you guys are seeing sounds very widespread but at least it seems like something GM can fix via a flash and it hasn't left anyone stranded anywhere right? Not a big deal. Trying to compare YOUR problems to Fords just makes you seem... well, I'll let you figure that one out.

I know a guy that has a cousin who's sister said she talked to a guy at a gas station that had problems with their 2011 Ford. They clearly ALL suck. HAH.

Every time I read this forum you guys crack me up. You have problems and start comparing them to issues you found on Ford forums, and blow them all out of porportion.

The 6.7's haven't had any real WIDESPREAD problems like this. The regens work great with no power loss, just a slight tone change from the engine bay. Regens happen at very consistent intervals and last right around 10 minutes _every time_. If I'm in a lot of city traffic i can regen at 150 miles. If I'm driving mostly highway it'll regen at about 300-350 miles. This seems very consistent with what everyone is seeing. It's FAR better than my 6.4l which seemed to have NO correleation between regens and driving habits and the power loss was nearly unbearable. On the 6.7 if I didn't see the regen notification or instant milage meter drop i'd never know it was in regen mode unless I was idling with the windows down next to a brick wall so I can hear the subtle change in engine noise(I first noticed it in a drive through and thought something was wrong).

Anyhow the issue you guys are seeing sounds very widespread but at least it seems like something GM can fix via a flash and it hasn't left anyone stranded anywhere right? Not a big deal. Trying to compare YOUR problems to Fords just makes you seem... well, I'll let you figure that one out.

Well, this is a GM-themed forum on the internet for cripes sake. What do you expect?

I know a guy that has a cousin who's sister said she talked to a guy at a gas station that had problems with their 2011 Ford. They clearly ALL suck. HAH.

Every time I read this forum you guys crack me up. You have problems and start comparing them to issues you found on Ford forums, and blow them all out of porportion.

The 6.7's haven't had any real WIDESPREAD problems like this. The regens work great with no power loss, just a slight tone change from the engine bay. Regens happen at very consistent intervals and last right around 10 minutes _every time_. If I'm in a lot of city traffic i can regen at 150 miles. If I'm driving mostly highway it'll regen at about 300-350 miles. This seems very consistent with what everyone is seeing. It's FAR better than my 6.4l which seemed to have NO correleation between regens and driving habits and the power loss was nearly unbearable. On the 6.7 if I didn't see the regen notification or instant milage meter drop i'd never know it was in regen mode unless I was idling with the windows down next to a brick wall so I can hear the subtle change in engine noise(I first noticed it in a drive through and thought something was wrong).

Anyhow the issue you guys are seeing sounds very widespread but at least it seems like something GM can fix via a flash and it hasn't left anyone stranded anywhere right? Not a big deal. Trying to compare YOUR problems to Fords just makes you seem... well, I'll let you figure that one out.

You know, I mostly agree with you. It seems as soon as we (GM guys) have issues we point the finger at you (Ford guys) and scream "well they're worse." As Domestic fans we should all be supporting each other. If we want to pass the buck let's at least pass it outside the Domestic market. ;)

I've driven tons of Super Duties (I used to pump concrete for a friend's family business, they've had every different Power Stroke going back to the 7.3 in the first Super Duty trucks). I like lots of things about most of them, but then they all had their draw-backs too. I still really like the '99 and '01 trucks they had that I drove, when it was still the 7.3 with the leaf spring front suspension. Simple, rugged, and easily lift-able. That said, the trans in those was junk. The 6.0 they had was a Lemon. The 6.4 they have has been great so far, other than power-loss on regen and fuel mileage overall. They don't have a 6.7 yet. But if you believe the magazine tests (which is a pretty risky proposition) the 6.7 does get handily beaten on all counts by the LML. But, on the flip-side it looks like the LML has two fairly common (though I wouldn't say wide-spread, based on my friends who manage/work at GM service departments) issues: smoke on regen (from the leak in the down-pipe joint) and the P0299.





So let's bring this back on topic! This is not a GM vs. Ford pissing match thread. THIS IS A THREAD FOR THOSE OF US DEALING WITH THE P0299 ISSUE TO TALK ABOUT OUR SYMPTOMS, DEALER EXPERIENCES, AND HOPEFULLY EVENTUAL SOLUTIONS. IF YOU WANT TO COMPARE GM VS. FORD VS. DODGE VS. WHATEVER OR OTHERWISE TAKE THIS THREAD OFF-TOPIC PLEASE JUST START A NEW THREAD.

So, with that said my light went out as per my previous reply and the truck ran great. I then had to leave for about a week on business, I'll be back tomorrow. Sat I go pickup my trailer (if the deal works out) but I'll just be towing it empty (28' all AL enclosed car hauler, prob somewhere 4-5k lbs with all the cabinets, awnings, winch etc. so very light for these trucks) and I'll let ya'll know how it goes.

Also, my buddy who manages parts and service for a GM dealers says he's only seen one LML with the P0299 outside of mine. They've actually sold a LOT of them (for reference he's already seen 3 come back w/ smashed DEF tanks from hard use... they sell a lot of rigs to ppl who use them hard). The GM engineers he's spoken to say they expect a fix in about a week.

-TJ

a fix for the 299 code or the DEF tanks?

Yes anybody heard anything yet about the flash?? Mine only threw the code once but really dont want to deal with it while towing.

Yes anybody heard anything yet about the flash?? Mine only threw the code once but really dont want to deal with it while towing.

Nothing yet. Mine also only threw it once and now it's fine. I towed a few hundred miles yesterday w/o issue. My buddy that manages a service dept did look up my VIN and my truck has both a PCM and TCM flash update out for it.

-TJ

Thanks TJ if you hear something let me know please, my dealer seems to be the last to know anything :(

Whats up with the reflash?
I'm taking mine in for a oil change tomorrow. Should I ask to have this done?
I'm not having any problems.

Thanks TJ if you hear something let me know please, my dealer seems to be the last to know anything :(

It's unclear if the flashes are related to the P0299 or just a general update.

Whats up with the reflash?
I'm taking mine in for a oil change tomorrow. Should I ask to have this done?
I'm not having any problems.

Just tuning and calibration updates. I'd have them run your VIN and see if there are any updates (which there will be unless your truck just got built) and have them update it. Might as well have the latest and greatest tunes.

-TJ

I'd have them run your VIN and see if there are any updates (which there will be unless your truck just got built) and have them update it. Might as well have the latest and greatest tunes.

-TJ

You can't just request a calibration update to your dealer. Now if an update solves a problem you are experiencing, that's different.

You can't just request a calibration update to your dealer. Now if an update solves a problem you are experiencing, that's different.

Anyone know what problem I'm having?

You can't just request a calibration update to your dealer. Now if an update solves a problem you are experiencing, that's different.

If you have a good service adviser and a decent relationship with your dealer you sure as heck can. When a VIN check indicates your vehicle has new PCM and/or TCM flashes out for it they're supposed to do it regardless of what the vehicle is in for. So as long as you can get them to check (which they should do anytime they have the vehicle in) then you should be able to get it done even if you're not having issues. I'm not suggesting you can ask for a calibration when there's no updates out, but if there are updates you absolutely can.

-TJ

If you have a good service adviser and a decent relationship with your dealer you sure as heck can. When a VIN check indicates your vehicle has new PCM and/or TCM flashes out for it they're supposed to do it regardless of what the vehicle is in for. So as long as you can get them to check (which they should do anytime they have the vehicle in) then you should be able to get it done even if you're not having issues. I'm not suggesting you can ask for a calibration when there's no updates out, but if there are updates you absolutely can.

-TJ

Where are you getting your information from? It is NOT protocol to do a VIN check for updated calibrations when a vehicle is brought in for service. If you look through GM's Global Warranty Management (which is supposed to be checked anytime a vehicle is brought in) which gives open recall and warranty information, there is nothing in there to check for updated programming. I have NEVER heard of GM telling us to check for program updates for shits and giggles.

To check for programming updates, you have to check in TISWEB, enter the VIN and see what is available. Even that won't show cal. the vehicle has in it, just what's available. Seventy five percent all service advisors I've ever dealt with wouldn't even have a clue how to do this.

If you think GM is going to pay to have your ECM programmed any time there is an update available just because you want to, and you don't have a problem/concern to justify it, you must mistake them for being more generous with their money than they really are.

You are correct about one thing though; if you have a good relationship with the advisor or the tech, they can have it programmed for you and kind of "fudge" the paperwork (as far as the concern ,cause and correction).

Anyone know what problem I'm having?

You'd have to give me your VIN so I can check and see what the calibration addresses.

Where are you getting your information from? It is NOT protocol to do a VIN check for updated calibrations when a vehicle is brought in for service. If you look through GM's Global Warranty Management (which is supposed to be checked anytime a vehicle is brought in) which gives open recall and warranty information, there is nothing in there to check for updated programming. I have NEVER heard of GM telling us to check for program updates for shits and giggles.

To check for programming updates, you have to check in TISWEB, enter the VIN and see what is available. Even that won't show cal. the vehicle has in it, just what's available. Seventy five percent all service advisors I've ever dealt with wouldn't even have a clue how to do this.

If you think GM is going to pay to have your ECM programmed any time there is an update available just because you want to, and you don't have a problem/concern to justify it, you must mistake them for being more generous with their money than they really are.

You are correct about one thing though; if you have a good relationship with the advisor or the tech, they can have it programmed for you and kind of "fudge" the paperwork (as far as the concern ,cause and correction).


Where are you getting your information from? As soon as I brought my 08 GMC in for a remote start install I gave them the vin at the service desk and he said to me that there was a PCM re flash and we will do that while the truck is in.

Where are you getting your information from?

The dealer I work for.

Well I have had the dealers on all my CTD do re flashes without me wanting some of them so they do, do them. But what I really care about is do they have a fix for the low boost yet or does anybody know when they will.

I get the same code and it seems to happen right after i punch the accelerator then have to let off quickly-unexpectedly, like when getting into traffic from an on ramp in a 55-65 MPH zone. I have been told is from engaging the turbo then quickly letting off the accelerator and its no big issue from what i have been told.

I am a GM man, this is my third Duramax with alison Trans, would not trade it for anything, making my first cross country pull with it over Christmas, and I know all will be good.

The dealer I work for.

Well that shows the quality at our dealerships!

And no there hasn't been an update yet. If all goes as the dealers say, the update or "fix" should be out the end of this week.

I get the same code and it seems to happen right after i punch the accelerator then have to let off quickly-unexpectedly, like when getting into traffic from an on ramp in a 55-65 MPH zone. I have been told is from engaging the turbo then quickly letting off the accelerator and its no big issue from what i have been told.

I am a GM man, this is my third Duramax with alison Trans, would not trade it for anything, making my first cross country pull with it over Christmas, and I know all will be good.

I definitely agree with that. Mine happened twice at highway speed and I rolled into the throttle where you would usually feel the turbo set you back a little bit in your seat and there was nothing there. Then the light came on and all was normal though.

Well that shows the quality at our dealerships!

And no there hasn't been an update yet. If all goes as the dealers say, the update or "fix" should be out the end of this week.

Thank you for demeaning my quality of work and knowledge.

I'll make sure my service writers, managers, and the guys in the shop get with you so you can tell us what we've been doing wrong all these years.

Sorry for the ditch; back on topic.

This code came up yesterday, took the truck to the dealer and he told me that GM is working on a calibration update to address the intermittent setting ot DTC PO299. Document ID:2550540

This code came up yesterday, took the truck to the dealer and he told me that GM is working on a calibration update to address the intermittent setting ot DTC PO299. Document ID:2550540

Yep, they updated the PI yesterday saying there is a new calibration that they will release.

what is the "PI"?

got the re program for the underboost code yesterday. Tech also showed me that the reporgram covered a DEF issue as well. Although i dont have much faith in this reporgram the underboost code hasnt resurfaced its head but I still have the DEF prob which was supposed to be fixed by the same reprogram.

got the re program for the underboost code yesterday. Tech also showed me that the reporgram covered a DEF issue as well. Although i dont have much faith in this reporgram the underboost code hasnt resurfaced its head but I still have the DEF prob which was supposed to be fixed by the same reprogram.

Feel any difference in power? I assume it's too early to see if MPG has changed.

-TJ

Thanks for letting us know that the re-program is now available. I'll call the local dealership tomorrow. It's a long time since I posted this thread.

Although mine only set the code one time Im glad the re program ready. What is the DEF issue?

Although mine only set the code one time Im glad the re program ready. What is the DEF issue?

x2. Mine came on around 330 miles but has never come back. Granted, I'm only at ~1500 miles now but about 600 of that was towing (first tow around 800mi).

-TJ

Here is the thread on the DEF issue that the same reprogram for the turbo under boost problem was SUPPOSED to fix. http://www.dieselplace.com/forum/showthread.php?t=401456 be sure to ask your tech what exactly the reprogram does so you know what areas of performance are being changed on your truck. I love GM but I have to admit I am starting to get fed up with this truck first P0299 then smoking from under the hood and dow this un resolved DEF problem all with less than 3000 miles and lese than 2 months old

So this morning my truck had the recalibration to correct the P0299 low turbo boost error. I specifically asked the service advisor what other issues the recalibration addressed and, after calling the tech, he said it ONLY deals with the P0299.

However, I had the feeling that I was being brushed off, and not given the straight goods.

So it there a tech out there with access to GM documentation who can give us the true story?

After reading Ted's post above I called my dealer to ask about the recalibration since I am having the P0299 issue as well. My service advisor ran my VIN and nothing came up. Only the bulletin showing that GM acknowledges the underboost problem and is working on a solution. Why whould some trucks have a fix but not others?

Ted how many times has yours thrown a code? So far mine has only done it once about 2,000 miles ago:confused: Did it right after a regen but went through the next regen with no problem

My truck threw the code twice over a 3 day period while towing my fifth wheel trailer on the way to Florida from BC in November. It has never happened without the trailer on the back, but that's not proof that it couldn't happen because we still don't have a comprehensive description of what was causing the problem.

The service record from this morning has very difficult to read handwriting but it says either "Reflashed PCM with update (H/10k)" or "Reflashed PCM with update (4/10k)". The item in brackets either starts with a 4 or an H.

Got this email from my dealership: If I go to service programming and enter your Vin. A new calibration is available. Looks like GM has not updated the bulletin as of yet even though the calibration is available. The only information listed is this “New calibration with diagnostic enhancements for DTCs P0299, P22A0 and P2202. Also addresses DEF tank warning messages”

I will be going in for a oil change and the flash in a couple weeks

I think you have a typo with code P22A0 because there doesn't seem to be any such code in standard DTC lists. However, all of the codes P2210 thru P2280 are connected with emissions system monitoring, so it is likely one of those. P2202 is connected with MOX sensing.

wife just towed a 40' trailer from NY to FL and back. Told her to keep the exhaust brake off, check engine light never came on for the entire trip.

It is interesting all you were towing trailers when you got your codes.

Saddly today I am lucky one to throw code this morning driving off my vessel this morning without out pulling a trailer. Outside temperature was about 24 F or -4 C. I only have 828 miles or 1333 km on the truck. Thanks to every one here I knew what check engine light was about after Onstar telling me I have varies codes related to turbo charger. Note: engine does sound different now bit like powerstroke while heavy with foot.

Make matters more interesting: Onstar represent wasn't able to contact dealer to set up appointment, O well not issue as it was only 7 am and normally dealers are not open this time in morning. I drive straight dealer and to my surprise building all locked up and employees standing around wondering why it is closed. As the dealer was close on Saturday for the stat so they should be open on the Monday one would think as all another dealers were open and business except banks and governement offices.

Well I could not wait around to figure what was happening there as I had get home to break up the cat fight with my wife and youngest daughter (my ears are still sore from phones calls yesterday as I work away from home). O well take in again on Wednesday after work.

Only good news was I was able put every family member back in line and straighten out two other kids at same time. I enought that BS.

Mine did not throw the code while towing, mine threw it while pulling out of Lowes??? Taking it in tomorrow for the flash

This morning my truck had the recalibration to correct the P0299 low turbo boost error. The check engine alert light came on while I was traveling I-10 from Houston this weekend. The dealer solved the issue and I am running fine again. The truck is great and did very well on the 1700 mile trip including an excellent ride for a HD truck, quiet, easy to drive, powerful and efficient. You can put it on cruise and it never shifts from 6th gear even on the high bridges. 70 mph gave me 19 mpg. Great truck!

Dealer let us know that the re-flash is available. I drove the truck for the first time this past weekend pulling 40' horse trailer, sure seemed sluggish vs our 2007 Classic. Hopefully things improve after our visit to the dealer.

Dealer let us know that the re-flash is available. I drove the truck for the first time this past weekend pulling 40' horse trailer, sure seemed sluggish vs our 2007 Classic. Hopefully things improve after our visit to the dealer.

Mine threw the PO299 code @ app. 3723 miles, and again @ 4895 miles and @ 5340 miles I was getting 18.5 mpg empty and interstate. Since they cleared the code my mpg has gone to 9 in the city and 15 on the interstate, and I am way down on power. Mine was "recalibrated" 12/27/2010. Only difference I see, is no more check engine light. I made a trip to Hot Springs AR this past weekend pulling a 18' carhauler and jeep that weighs app. 4300lbs, running 70-72 and got app. 10 mpg!!! And, no power to pass, really scary. This truck ran like a bat out of hell when I first got it, but since it went in the shop, It is a POS! Oh, the dealer says nothing is wrong with it... Yea, right.
Believe it or not, I'm actually starting to miss my '07 Powerstroke, and it didnt have a payment:mad:

Well great im going in today for the reflash, since my truck only threw a code once i wondering if I want to get it done. Anybody else that had the reflash had performance problems afterwards?

No change in performance after the reflash. Goes like a bat out of hell.

Mine threw the PO299 code @ app. 3723 miles, and again @ 4895 miles and @ 5340 miles I was getting 18.5 mpg empty and interstate. Since they cleared the code my mpg has gone to 9 in the city and 15 on the interstate, and I am way down on power. Mine was "recalibrated" 12/27/2010. Only difference I see, is no more check engine light. I made a trip to Hot Springs AR this past weekend pulling a 18' carhauler and jeep that weighs app. 4300lbs, running 70-72 and got app. 10 mpg!!! And, no power to pass, really scary. This truck ran like a bat out of hell when I first got it, but since it went in the shop, It is a POS! Oh, the dealer says nothing is wrong with it... Yea, right.
Believe it or not, I'm actually starting to miss my '07 Powerstroke, and it didnt have a payment:mad:

Maybe you have a problem that a calibration won't fix.

When I first got the code I was not towing. I got the code twice last week when towing down to Glamis (~600 miles w/ a ~10k lbs enclosed trailer/toys) and then again on my way back up. On the way down it was at the very end of the tow (last ~50mi) so I wasn't too worried. On the way back up it was at the very start of the trip. Both times OnStar confirmed P0299. It's hard to say, but it did feel like I was down on power a bit until the light cleared... but it could have been all in my head. It still yanked the trailer up the famous "Grapevine" here in CA fast enough but I wasn't happy about it.

-TJ

Had the reflash and all is well, I did have one question it says they found a p0299 code which i know what that is and also P20EE what the heck is that

Maybe you have a problem that a calibration won't fix.

Thats exactly what I'm thinking. My loss of power and fuel mileage began after the first trip to the dealer to clear the code... I was hoping the recalibration would get it back to where it was. I record every fuel event, recording both the DIC, and actual numbers. I have documented proof that my fuel numbers have dropped off app. 4 miles per gallon since the code was cleared @ 3726 miles.
Something is wrong with this truck!!!

Please let us know what the dealer finds is the cause of the low mpg KeithG.

Please let us know what the dealer finds is the cause of the low mpg KeithG.

Sure, not a problem...

I just took mine in yesterday for both the smoking issue and the P0299 (I have gotten the light 3 times for it). I'll report back if the new flash changes MPG or seat of the pants power etc. once I get it back.

-TJ

I had the new flash installed today.

Not after getting pissed off and telling sale man come pick up the truck. As the service department refused to check for a code and trouble shoot as the check engine went out. I would be charged for the checking for codes. Then sale man went to service manager told him it was new vehicle, the Onstar was involved and that I am engineer with lots of diesel engine experience whom knows how ECM data logging works. Once I explained the what Onstar told me the service manager agreed with me. Then then preform the code check sure enough it under boost code was there as I stated. There were some very pissed off service guys as manager given them s..t because they tried to BS me.

So far there does not seem to be any change in performance.

I wish the service manager would have to put out $50 plus grand and then have another service manager tell them.......sorry......cost you to have codes read. They have to understand that this is a NEW system and there are going to be glitches......and if the glitches are not identified and reported...........there will never be a permanent fix. Think everybody that has problems with their LML has to be stern with the service manager and make sure they do their job right and report the shit to GM!!!!

I got the P0299 code but the check engine light went off, after about 10 ignition cycles, before I could get it to the dealer. Then, the service people refused to perform the reflash because they had "scanned PCM, no codes present at this time."

Alls they need to do is look run your vin to see if truck is eligible for the reflash.

I tell you, I see what everybody is talking about when they say GM service SUCKS. I leave for Afghanistan on Sunday so I really don't have time to F-around with this stuff. I dropped my truck off early Wed (with an appointment) and told them exactly what was going on: the P0299 3 times (I even showed them pictures of the gauge cluster each time it happened with show the light and miles on the truck when it happened) and the smoking on regen. I provided them the appropriate bulletin IDs and even let them know that I had a buddy who runs a service dept (that is unfortunately hours away from me) run my VIN and verify there is a new flash for the truck.

So they pull my loaner up... it's a high mileage '04 Malibu that looks like complete dog dick. It's missing all but one hubcap, has had obvious cheap/home body work done, and better yet it's smoking heavily from under the hood. They're ready to let me take off in this thing and I pop the hood. The smoke (well steam really) is visibly coming from between the block and head. I tell them there's no way I'm taking it. So they get Enterprise to pick me up. I get an also high-mileage (for a rental - and I travel/rent ALL the time for business I know what's appropriate and not) Cobalt. How is that an equivalent replacement for my diesel 3/4 ton truck?

I'm busy trying to get out the door for Afghanistan and I had an all day team off-site yesterday that was back to back to back to back (etc.) meetings so I didn't have time to hound the service dept on the phone. I finally get a call around close of business yesterday and they've done next to nothing. They hadn't used TECHII to force a regen yet, they say there is no updated flash for my truck, and they say they'll need to do an "extended road test" to diag the check engine issue. I let them know the extended road test is not going to be okay with me. a) the first time the light happened was ~300 miles the second was ~3400 so what are they going to to do, drive it 3,000+ mi???? b) the second and third times it happened were with a trailer, are they going to put 10k lbs behind it to check c) I don't want some ****ing random dude driving my truck all over.

I did some yelling and screaming and they're supposed to call me back this AM so we'll see where that takes things. I can say that my stupid Lexus that turned out to be a lemon was a < $40k car (I bought it barely used for $29k actually) and my D'max stickered at like $58k+ (I got it for $53ish) and I got treated a million times better taking the Lexus in for service.

These are damn near $60k trucks, I'm not saying they should never break. They are machines, they break. Sure, most of these issues we're all having feel like they should have been caught in R&D but oh well. I'm just saying I should be treated a little better than this!!!!!!!!

-TJ

TJ:

I had similar issues for my service adviser. Have them to check for GM notices PIP4846B "Reprogem ECM with new calibration with diagnostic enhancements for DTCs P2099,P22A0 and P2202" I got this directly from my service report for work carried out yesterday.

Hi all
I too am having the same problem Keith is; the truck runs great until the 30th of November with 1800 miles on the odometer and the PO299 error code happens :(
It occurred while pulling a moderate up grade on I-80 between Rocklin and Newcastle with no load or trailer. I also haven’t ever noticed a regen happen with the truck and I have about 3400 miles on it, not that they haven’t happened I guess but I sure haven’t noticed them.

Anyway I take it straight to the dealership I bought the truck from the next morning and they can’t find anything wrong, we know it’s an issue, blah blah blah, they clear the error code and I drive 45 miles home. The truck is a little sluggish on the trip home and it feels like the high idle is stuck on, I am even standing on the brake at the stop lights because the motor is running at about 900 RPM’s. Then I notice the fuel mileage has dropped off, like 5 to 6 gallons per mile dropped off, and the truck is still idling at 900 or better RPM’s. I finally cleared the high idle by shutting the motor off, depressing the accelerator pedal and pushing the brake pedal three times in rapid succession, and I have the LTZ with the DIC where you can control the high idle in the set up and it has always been set to off. So now I am fighting with the dealership service department because they’re telling me there are no fixes for the problem, which I now know is horse***t.

Problem is I love the truck, it performed flawlessly for the first 1800 miles and it still is a wonderful vehicle but I’m going broke fueling it and I can’t help but think I’m wearing something out driving it in this condition. And last night the high idle kicked back on only this time I couldn’t get it to clear.

I have an appointment with the dealership Monday afternoon and I’ve written down the re-flash GM notice PIP information so I hope to have some resolution but the service guy is telling me that my VIN isn’t identified for the upgrade and they are being told to monitor the vehicles with the just the PO299 error codes because there isn’t a fix out yet :confused:
I am finding it very difficult not to get pissed at spending $54K and end up getting the cold shoulder when there is a problem :mad:

Sorry for the ranting but is there anything I am missing, is there something else to be done that I can tell the dealership :confused:

Hi all
I too am having the same problem Keith is; the truck runs great until the 30th of November with 1800 miles on the odometer and the PO299 error code happens :(
It occurred while pulling a moderate up grade on I-80 between Rocklin and Newcastle with no load or trailer. I also haven’t ever noticed a regen happen with the truck and I have about 3400 miles on it, not that they haven’t happened I guess but I sure haven’t noticed them.

Anyway I take it straight to the dealership I bought the truck from the next morning and they can’t find anything wrong, we know it’s an issue, blah blah blah, they clear the error code and I drive 45 miles home. The truck is a little sluggish on the trip home and it feels like the high idle is stuck on, I am even standing on the brake at the stop lights because the motor is running at about 900 RPM’s. Then I notice the fuel mileage has dropped off, like 5 to 6 gallons per mile dropped off, and the truck is still idling at 900 or better RPM’s. I finally cleared the high idle by shutting the motor off, depressing the accelerator pedal and pushing the brake pedal three times in rapid succession, and I have the LTZ with the DIC where you can control the high idle in the set up and it has always been set to off. So now I am fighting with the dealership service department because they’re telling me there are no fixes for the problem, which I now know is horse***t.

Problem is I love the truck, it performed flawlessly for the first 1800 miles and it still is a wonderful vehicle but I’m going broke fueling it and I can’t help but think I’m wearing something out driving it in this condition. And last night the high idle kicked back on only this time I couldn’t get it to clear.

I have an appointment with the dealership Monday afternoon and I’ve written down the re-flash GM notice PIP information so I hope to have some resolution but the service guy is telling me that my VIN isn’t identified for the upgrade and they are being told to monitor the vehicles with the just the PO299 error codes because there isn’t a fix out yet :confused:
I am finding it very difficult not to get pissed at spending $54K and end up getting the cold shoulder when there is a problem :mad:

Sorry for the ranting but is there anything I am missing, is there something else to be done that I can tell the dealership :confused:

Good luck, and keep us posted... Mine is no better after the recalibration, still sluggish, and fuel mileage is crap. Honestly, it feels like they de-tuned it!

I think service is still a weak link in the customer satisfaction equation. I'm not sure where the blame is.

TJ:

I had similar issues for my service adviser. Have them to check for GM notices PIP4846B "Reprogem ECM with new calibration with diagnostic enhancements for DTCs P2099,P22A0 and P2202" I got this directly from my service report for work carried out yesterday.

They found a cracked coolant overflow bottle on my truck too. I told them to fix that so it is drivable and I'd take it elsewhere.

After the fix I took it up to Abel Chevrolet in Rio Vista and they took great care of me. Of course, I know the parts manager and race 'vettes with him. But if every Chevy dealership ran its service like Abel does they'd be good to go.

Abel found all the updates for the PCM etc. so they should be able to fix her all up. I'm also having them do Amsoil in the Motor, Trans, TCase, and both Diffs while it's there. :)

Hi all
I too am having the same problem Keith is; the truck runs great until the 30th of November with 1800 miles on the odometer and the PO299 error code happens :(
It occurred while pulling a moderate up grade on I-80 between Rocklin and Newcastle with no load or trailer. I also haven’t ever noticed a regen happen with the truck and I have about 3400 miles on it, not that they haven’t happened I guess but I sure haven’t noticed them.

Anyway I take it straight to the dealership I bought the truck from the next morning and they can’t find anything wrong, we know it’s an issue, blah blah blah, they clear the error code and I drive 45 miles home. The truck is a little sluggish on the trip home and it feels like the high idle is stuck on, I am even standing on the brake at the stop lights because the motor is running at about 900 RPM’s. Then I notice the fuel mileage has dropped off, like 5 to 6 gallons per mile dropped off, and the truck is still idling at 900 or better RPM’s. I finally cleared the high idle by shutting the motor off, depressing the accelerator pedal and pushing the brake pedal three times in rapid succession, and I have the LTZ with the DIC where you can control the high idle in the set up and it has always been set to off. So now I am fighting with the dealership service department because they’re telling me there are no fixes for the problem, which I now know is horse***t.

Problem is I love the truck, it performed flawlessly for the first 1800 miles and it still is a wonderful vehicle but I’m going broke fueling it and I can’t help but think I’m wearing something out driving it in this condition. And last night the high idle kicked back on only this time I couldn’t get it to clear.

I have an appointment with the dealership Monday afternoon and I’ve written down the re-flash GM notice PIP information so I hope to have some resolution but the service guy is telling me that my VIN isn’t identified for the upgrade and they are being told to monitor the vehicles with the just the PO299 error codes because there isn’t a fix out yet :confused:
I am finding it very difficult not to get pissed at spending $54K and end up getting the cold shoulder when there is a problem :mad:

Sorry for the ranting but is there anything I am missing, is there something else to be done that I can tell the dealership :confused:

The high-idle is just regen. It should only happen every ~500mi (more if you tow heavy) but when it does you'll idle high and MPG will go to crap (since it's literally injecting fuel into the exhaust). That said take your truck to Abel in Rio Vista, ask for the service writer Nick and/or Rich the parts manager and tell them TJ sent you over.

Good luck, and keep us posted... Mine is no better after the recalibration, still sluggish, and fuel mileage is crap. Honestly, it feels like they de-tuned it!

That's what I'm worried about. I hope the "updates" don't just tell it to boost less so you don't get the P0299 when the turbo doesn't actually hit the boost the PCM wants (that's what the code is for, I've been told the threshold is 12psi less boost than expected by the PCM).

I think service is still a weak link in the customer satisfaction equation. I'm not sure where the blame is.

I blame each individual dealership, but also GM for not holding them to a higher standard. Abel proves a GM dealer can run a good service department and treat their customers right... so it can be done on a GM dealer budget.

-TJ

Think you ought to call GM and complain about the service you got at your dealer.....and of course let them know how good you were treated at the other dealer!!!!! Hopefully GM will communicate with your dealer and set them straight.

What I want to know is does the re-flash really fix the issue of P0299? I have this code today and will be going to the dealer tomorrow. Mileage dropped from 18.2 to 13.5 as well...

knock on wood so far mine is working, mileage is back to where it was when i bought the truck and all is well

Thanks Mike..

What I want to know is does the re-flash really fix the issue of P0299? I have this code today and will be going to the dealer tomorrow. Mileage dropped from 18.2 to 13.5 as well...

I wish you the best of luck... My mileage has never came back up, please let me know if yours does. I am currently compiling information to confront my dealer, so anything you have will be helpful.

Thanks

Getting ECM reflash on mine tomorrow for DEF problem. Wondering.....with the reflash......will it include all fixes GM has come up with on the LML?

Stopped by the dealer this morning, was in and out in less than 10 minutes. Mileage had dropped to 12.1 by the time I got there, but on the way home it was 16.4 which is about right for that road. So far so good.. If something changes I will update.

Getting ECM reflash on mine tomorrow for DEF problem. Wondering.....with the reflash......will it include all fixes GM has come up with on the LML?

Yes it covers several issues. My light came on for a few min, went away and never came back. I didn't notice anything different. I just had them flash it anyways. I did notice an increase in mpgs but it could also be that my truck finished its regen cycle.

Thanks. I have only had the light once also.....but was only 5 miles away from the dealers just after I picked it up NEW. Thought the dealer should have done the reflash before I picked it up since the truck was on the lot for a month and they are aware of the problems with the def. Hope this corrects all ills!!!!!

I just got my first P0299 this morning. Brand new 2011 LML with ~500 miles on her. Air temp was about 22F and I was about half way into a 6 mile drive to work. I told my service advisor about this thread and he is going to have the techs do a PCM flash to start with. I am crossing my fingers that it does not reoccur after that. My mileage has been about 14-16 MPG with a mix of city and highway. I'll post a follow-up on Monday!

For those that have had the code P0299 and have gotten a fix, please keep us posted on the MPG and the code coming back.

From what I read, there are a handful of people on this thread that have had this issue (P0299). I would like to hear from other LML owners that have had trouble free ownership. If there are 10 out of 100 trucks that have this issue, then the problem is not so "widespread". I would be interesting to see how many people are running fine.

Thanks.

Got it yesterday, Onstar ran the diagnostics and said it was safe to drive. Took it to the dealer this morning.They listed it as "P0299 Turbo Charger Engine Underboost" Reprogrammed ECM CODE 11E13. Took 45 minutes from the time I handed them the keys. Runs great now. I had 6758 miles on the truck.

Driven 70 miles since then, I reset the DIC mileage when I left the dealer and it was reading 18.3 mpg tonight when I got home.

This morning i was taking my truck in to have the things fixed they screwed up at delivery.. pulls to left (Aligned twice already), Forgot the ezlift tailgate from factory, smoke under hood during regen (Gaskets), And during remote start truck shuts off and horn goes off. Well anyhow on the way in it threw a code 'po299'. They said they had to do the recal software. I'm glad it happened when it did but i hope the truck is fixed now. I'm worried from reading this thread. I hope the recal doesn't detune the truck and make it gutless.

Just a note here for those of you have been recording the mpg since the P0299 reflash.

The mpg you are measuring is dependent upon when a regeneration takes place. If there was a regen just before you had the reflash, you will be experiencing high mpg, maybe even as high as 20 mpg on the freeway. It is easy to jump to the conclusion that the reflash increased the mpg, but we don't have enough information in this forum to be able to come to that conclusion.

There are posts where others are blaming the reflash for LOW mpg, but if a regen started shortly after the reflash, and the DIC had been reset, you would expect low mpg.

Based on the posts in this and other threads which deal with mpg, I personally think there is something else going on which is causing low average mpg on some trucks. In my own case, I have been carefully recording the milegage between regenerations, which are quite noticeable on the 2011s. At this stage I have enough data to show a dealership that regens are occuring VERY frequently on my truck, on average about every 180 to 200 miles, which is not normal because it should be around 500 miles. The result is low average mpg, no more than 13 mpg, even in the best driving conditions.

A significant change that was made to the emissions system for the 2011 model year was the addition of a 9th fuel injector, in the exhaust manifold, instead of using the engine injectors to add fuel to the exhaust during regens. I can't help wondering if some of our trucks are not dispensing the correct amount of fuel through that 9th injector, thereby contributing to excessive fuel use.

I'll be taking the truck to a dealership soon, maybe this week, and will hopefully get some meaningful analysis done. You can be sure I'll post the results.

It will be interesting to see what comes up!!!! And.....what GM will do about it if the 9th injector is throwing out excessive fuel, could effect alot of us.

Forgot............Good Luck!!!!!

Just a note here for those of you have been recording the mpg since the P0299 reflash.

The mpg you are measuring is dependent upon when a regeneration takes place. If there was a regen just before you had the reflash, you will be experiencing high mpg, maybe even as high as 20 mpg on the freeway. It is easy to jump to the conclusion that the reflash increased the mpg, but we don't have enough information in this forum to be able to come to that conclusion.

There are posts where others are blaming the reflash for LOW mpg, but if a regen started shortly after the reflash, and the DIC had been reset, you would expect low mpg.

Based on the posts in this and other threads which deal with mpg, I personally think there is something else going on which is causing low average mpg on some trucks. In my own case, I have been carefully recording the milegage between regenerations, which are quite noticeable on the 2011s. At this stage I have enough data to show a dealership that regens are occuring VERY frequently on my truck, on average about every 180 to 200 miles, which is not normal because it should be around 500 miles. The result is low average mpg, no more than 13 mpg, even in the best driving conditions.

A significant change that was made to the emissions system for the 2011 model year was the addition of a 9th fuel injector, in the exhaust manifold, instead of using the engine injectors to add fuel to the exhaust during regens. I can't help wondering if some of our trucks are not dispensing the correct amount of fuel through that 9th injector, thereby contributing to excessive fuel use.

I'll be taking the truck to a dealership soon, maybe this week, and will hopefully get some meaningful analysis done. You can be sure I'll post the results.

Great info. How are you determining if you're getting regens when doing freeway driving? For example, I pulled a ~10k trailer ~1500 miles over New Years week and couldn't notice a regen as it was nearly all freeway going. I'm sure I regen'ed several times since I was towing and all, but I never happened to have a regen when I was in traffic so I didn't notice the elevated idle or smoke.

On the trip I was seeing anywhere from 10-13mpg (again, towing a ~10k enclosed car trailer) hand-calculated.

-TJ

I have detected regenerations occuring while freeway driving by constantly checking the mpg on the DIC.

For example, a few days ago I drove from Fort Myers to Tampa on the freeway. After entering the freeway at Ft Myers, and setting the cruise control at the speed I wanted to travel, I reset the mpg.

The mpg very quickly stabilized at around 19 mpg, but, because it was being measured over a relatively short distance, as soon as a regeneration started I noticed the mpg beginning to drop, instead of remaining steady.

As soon as this happened, I again reset the mpg. It very quickly stabilized again, but this time at around 8.5 mpg. It was therefore obvious that something was happening that consumed a lot of fuel.

I continued to monitor the mpg, and after about 20 miles the mpg started to rise again, so I reset the mpg. Once more, the mpg stabilized at 19.6 mpg, and remained there for the rest of the trip to Tampa.

I have detected regenerations occuring while freeway driving by constantly checking the mpg on the DIC.

For example, a few days ago I drove from Fort Myers to Tampa on the freeway. After entering the freeway at Ft Myers, and setting the cruise control at the speed I wanted to travel, I reset the mpg.

The mpg very quickly stabilized at around 19 mpg, but, because it was being measured over a relatively short distance, as soon as a regeneration started I noticed the mpg beginning to drop, instead of remaining steady.

As soon as this happened, I again reset the mpg. It very quickly stabilized again, but this time at around 8.5 mpg. It was therefore obvious that something was happening that consumed a lot of fuel.

I continued to monitor the mpg, and after about 20 miles the mpg started to rise again, so I reset the mpg. Once more, the mpg stabilized at 19.6 mpg, and remained there for the rest of the trip to Tampa.

Ah, gotchya. I hadn't reset my average MPG since I got the truck since I was trying to monitor long-term. I'll probably try your method once I get the truck back (and I get home).

-TJ

Its been almost a week since I had the re-flash done. So far so good, power is still there and mileage is what it was before I had p0299. I hand figure my mileage every time, always have. Good luck to everyone else.

So, based on everything I've just read, the 18-20mpg is not an accurate number for the LML. Has anyone measured MPG combined over sereral thousand miles? GM claims that the LML is suppossed to be 11% more efficient. Is that the case here?

I have detected regenerations occuring while freeway driving by constantly checking the mpg on the DIC.

For example, a few days ago I drove from Fort Myers to Tampa on the freeway. After entering the freeway at Ft Myers, and setting the cruise control at the speed I wanted to travel, I reset the mpg.

The mpg very quickly stabilized at around 19 mpg, but, because it was being measured over a relatively short distance, as soon as a regeneration started I noticed the mpg beginning to drop, instead of remaining steady.

As soon as this happened, I again reset the mpg. It very quickly stabilized again, but this time at around 8.5 mpg. It was therefore obvious that something was happening that consumed a lot of fuel.

I continued to monitor the mpg, and after about 20 miles the mpg started to rise again, so I reset the mpg. Once more, the mpg stabilized at 19.6 mpg, and remained there for the rest of the trip to Tampa.



I've just reached a 1000 miles on my truck. As far as I can tell I've had two regens in that time. I do a mix of highway and city driving on my way to work. So far by DIC the truck seems to avg. around 15.4 mpg. When in regen it drops to 13.8 mpg. I can tell when it's in regen also because when I get home the truck stinks even though I haven't noticed the smoking problem that others have.

So, based on everything I've just read, the 18-20mpg is not an accurate number for the LML. Has anyone measured MPG combined over sereral thousand miles? GM claims that the LML is suppossed to be 11% more efficient. Is that the case here?

I've recorded nearly every tank with my LML (just over 4k miles now), only missed a few. I need to throw them in my spreadsheet and post the numbers. Probably half of my miles are towing though.

-TJ

Well i got my truck back yesterday and no more code, no loss of power and MPG seem the same. Too bad they can't line the wheels up proper 3 times now...

I got mine back today also. Monster power and torque have returned! I haven't driven enough yet to check the mileage though. Now I am holding my breath for when/if the DEF issue surfaces. Crossing my fingers! ;)

Service invoice states:
"Cust states service engine soon light is on. Retrieved code P0299. Reprogrammed ECM per TSB"

Any techs that can confirm an actual TSB has been issued vice a PI ?

I just received some interesting information from a reliable source about the P0299 code. Apparently there was a programming glitch associated with the air pressure/altitude sensing system. If the system returned a reading of zero, equivalent to sea level under certain conditions, the program for turbo vane control tried to divide by zero, which gave a meaningless result (infinity) and in turn caused the vanes to open fully, reducing power and causing the code.

I just received some interesting information from a reliable source about the P0299 code. Apparently there was a programming glitch associated with the air pressure/altitude sensing system. If the system returned a reading of zero, equivalent to sea level under certain conditions, the program for turbo vane control tried to divide by zero, which gave a meaningless result (infinity) and in turn caused the vanes to open fully, reducing power and causing the code.

Hmm, that make sense (strangely enough) and would explain the conditions we're all experiencing. When I had the GM tech rep on the OnStar line they told me P0299 indicated a deficiency of 12psi or more from the expected boost value. 12psi under-boost would explain the dog-like performance we've all occasionally experienced. I can't wait to get my truck back as the beast it was under all conditions.

-TJ

Strangely enough, I was near ElCentro ( sea level and below ) when I got the 0299, but it went away, never to be seen again

Strangely enough, I was near ElCentro ( sea level and below ) when I got the 0299, but it went away, never to be seen again

Actually, I was near or in El Centro when I got the P0299 one time as well (towing down to Glamis). Another time I was in Santa Cruz along the cliffs (so about 20 feet above sea level ;) ). I don't think I've ever gotten the code much more than a few hundred feet from sea level... that said I've probably spent 90% of the 4k miles on my truck within a few hundred feet of sea level so it might not mean anything...

-TJ

I think it might be a wise decision, for any owner taking the truck back to the dealership for scheduled or warranty service, to ask for the P0299 reflash.

Hi all
Sorry about the delay but life got really busy the last few weeks. I had the truck re-flashed the middle of January and the power came back nicely. The service department manager said the update would only address the turbo boost issue and not the fuel mileage issue. And he was correct, the fuel mileage is still in the low to mid teens no matter what type of driving we do and it gets absolutely awful when a regen occurs, which is really depressing because the mileage was absolutely phenomenal until the PO299 error occurred. I have been following the recommendations about winter driving and using the fuel additive religiously without any changes.
At this point I don’t have the time, money for fuel or patients to keep driving back and forth to the dealership so we’re going to park the truck, drive the wife’s car more and I’ll start pestering them via the phone. Kind of depressing that some trucks are experiencing this problem and some a still getting those awesome mileages

My mileage has been terrible as well after the reflash. I sincerely hope there is a new flash or something to address the mileage issue. It's getting very annoying with diesel prices on the rise.

The reflash should have nothing to do with fuel economy. It was a correction to the programming for the variable vanes in the turbocharger.

Stepping out on a limb here, but if the flash results in a higher than before boost pressure, this will reduce fuel economy, as more engine horsepower will be used to spin the turbo. One would not expect the charge in boost pressure to significant enough to impact mileage, but obviously something is going on here.

The flash was not designed to increase boost pressure. It corrected a programming fault where the system divided by zero under certain altitude and air pressure conditions, particularly near sea level. This resulted in a number which the system could not process (infinity), and caused the turbo vanes to open fully instead of adjusting appropriately for air pressure and altitude. Turbo boost dropped, and a fault code was triggered. If there are mpg issues, they are likely being caused by something else.

I guess my point here is that something is not working correctly. There appears to be some correlation between those having had the update and poor fuel economy. Its a guess, but one possibility is somewhere between the initial programing error and the update the overall results is that there is more boost than before setting the error code-which would result in poor fuel economy. It appears there is more going on than a simple divide by zero error, at least for those still having a problem. Where their mileage dropped off at the time of the error code it is somewhat more likely that the two are related. I wonder-is the mileage drop approximately the same after the update as before? If the drop is unaffected by the update (no change in the pre and post error message mileage drop), it would seem that they are unrelated. If it is still bad but by a different amount, it would seem more likely to me that the update has changed something but still has not fixed the whole problem.

I wonder if those who are still having trouble with fuel economy after the update are the same who drove their trucks for a little while after having set the code. If the vanes are open and boost pressure is reduced, fuel economy should increase, all things being equal. That the fuel economy drops indicates to me that either injection timing is being retarded or the engine is over fueling. (perhaps the low boost pressure is outside of the fueling map). If the engine is being over fueled then a large amount of soot is being produced, clogging up the DPF. In addition, if the engine is being over fueled, there will not be sufficient oxygen in the exhaust stream to support a regeneration of the DPF, even if the computer tries to run one with the code set. I suspect for those who have driven their trucks for an extended amount of time with the code set will have clogged DPF’s. This will reduce their fuel economy in two ways: (1) increased back pressure (2) the computer will be trying to regenerate the DPF which will result in a greater amount of fuel use than normal. I wonder if for some it will just take a little longer for fuel economy to creep up. I suspect light freeway driving would enhance the cleaning of the DPF (light engine load, higher engine speed).

Interesting theory Sparky21, but I don't think that's what is happening, for two reasons:

1.
The Code is triggered when the faulty program tries to divide by zero, and the vanes do open fully at the time. However, they do not remain open indefinitely. I do not know exactly how long the "vanes open" situation persists, but unless the combination of air pressure and altitude persists indefinitely, things return to normal very quickly. That's why some folks, including me, witnessed the code two or more times over a couple of hours.

2.
My truck has just gone through a series of tests at a dealership where a reading was taken of average mpg and the total number of regenerations since new. A regeneration was forced so that the temperatures at the exhaust system sensors could be checked. In addition, a backpressure test on the DPF was done before and after the forced regeneration. All of this was done as part of the investigation of mpg.

It turned out that the miles between regenerations was 410, which is at the low end of the acceptable range, but still OK. Exhaust system temperatures were normal, and backpressure in the DPF was virtually non existent after regeneration. The investigation continues, and I'll share any useful information as it becomes available, but for now there is nothing in the emissions system performance which adequately explains the lower than average mpg.

The distance between regens, being at the low end of normal, MIGHT suggest that the DPF is filling more quickly than average, requiring more regenerations, but the regenerations themselves are normal.

As for a lack of oxygen in the exhaust stream if the engine overfuels, this would not be the case. The role of the DOC, the Diesel Oxygen Catalyst, which is in the exhaust line before the DPF, is to produce oxygen from the abundant NOX (Oxides of Nitrogen) in the exhaust so that the injected fuel during regeneration will burn nicely.

Just a quick update.. Four thousand miles have been put on the truck since P0299. All has been fine since the re-flash. Mileage and power are back to their normal levels, so for me all is well
Good luck to you.
Jp

Thanks thats good to hear, so far so good with mine also

Oh well, my turn in the barrel. Check engine light came on today @ 2360 miles. Called On Star, they said it was the infamous P0299. OK to drive just reduces engine performance but should take it in to the dealer.

Bayoubengal, are you near, or were you near sea level when the code set ??

Was doing some catching up on reading in this thread. I have noticed my truck has been going through regen around 450 miles. Some things I noticed with mine when it set the code was I was near sea level but in a parking lot?? After the code I noticed higher then normal idle plus on normal take offs my boost would go as high as 14lbs when normally it is around 6-8 lbs. Also when I went in for my last oil change I had around 4,000 miles on the truck since the last one and only could put in 1 gallon of DEF?? My soot mass is the same as it was on day one it goes to a level fast then sits there then it seems to go up in stages until the gauge reaches around 119 grams then it regens.

I figured the reason for the lower mile regens was do to the fact I do not tow in the winter and all my miles are in town or short hops on country roads with several steep hills which would produce more soot. Tested my mpg on mostly all freeway last weekend and I am still getting between 19 and 21 mpg so that seems to be the same.

Regen at 450 miles is in the normal range. I don't have any specific information about what to expect with boost levels after experiencing code P0299, but it becomes a moot point once the reflash has been done.

Interesting re your DEF usage. I also seem to be getting a LOT of miles out of a tankful of DEF. Unfortunately, the lack of a gauge makes it impossible to know how much fluid is still in the tank, but I think I've only used about 4 gallons in 10,000 miles. Don't know if it's worth worrying about though, because the usage is based on the amount of NOX in the exhaust, as measured by a sensor, and it doesn't impact at all on engine performance.

True and I dont know if it has anything to do with it but this all changed with the colder weather.

I've been in Florida since late October, so I think we can scratch the weather off the list of possible causes of low use of DEF.

Ted, The engine light came on while towing my 5th wheel. It happened a few miles out of New Orleans, so it was below sea level. I called my dealer today and the service mgr said they just reflashed another truck this morning.

OK Bayoubengal, your experience is consistent with sea level triggering. Thanks. Shouldn't happen again after you get it reflashed.

Great thread, thx for inputs.

I had my own issues with P0229. See thread here: http://www.dieselplace.com/forum/showthread.php?t=411310


The difference in my case is that no check engine light came on yet the code was stored and found by dealer after fighting through their reluctance to check it out (I had a trans issue at 150 miles and wanted a recheck now to verify a clean bill of health). The truck seems sportier now after flash but I didn't do any back to back speed tests to verify as I didn't know a problem was present. I am still getting used to this truck (only 2 months old) so I wasn't aware that I was at a loss of power, I just assumed all was normal.

Questions:
-What device are you all using to see and then reset your codes, especially if a CEL does not come on? I have seen some wireless OBD devices that can report to my Droid/Smart phone. Recomendations?
-Also, what is the target boost when everything is working correctly? What was boost when "underboosting"? How much power loss does this represent?
-Does 3 (or more) P0229 occurances qualify as the Lemon Law (Song-Beverly act)?
-What is the best way to convince dealer to check for CELs? They didn't want to check in my case as no CEL was on the dash yet there was one discovered internally once they bothered to scan.
-Not clear about this but has anyone continued to have this code come up again after the reflash or did that solve the P0229 issue?

BTW, my MPG has fluctuated between 12-22, not towing. It currently aves about 18 in moderate fwy traffic, will check if effected by this reflash (performed yesterday).




Additional bitching....... They charged me the "bend over rate" for the oil change service as this is a big mean diesel truck which already hurt. Then they wanted to charge me extra labor (about $30 plus the cost of DEF at $12/gal) for having to add DEF! I realize that the cost of the DEF would be extra but not that there would be additional labor. After all, isn't it similar to adding wiper fluid or coolant etc? BTW, the RO said "top off all fluids"......

Love my truck but starting to hate the owner/dealer relationship :confused:

Well your getting reamed on the DEF its 4.95 per gallon at most dealerships

Well your getting reamed on the DEF its 4.95 per gallon at most dealerships

I told them not to do it. A good friend owns a lube center who will be doing services for me from now on. My only concern is that I wont have access or info regarding updates if I dont return to dealer. Hmmmm.....

Questions:
-What device are you all using to see and then reset your codes, especially if a CEL does not come on? I have seen some wireless OBD devices that can report to my Droid/Smart phone. Recomendations?
-Also, what is the target boost when everything is working correctly? What was boost when "underboosting"? How much power loss does this represent?
-Does 3 (or more) P0229 occurances qualify as the Lemon Law (Song-Beverly act)?
-What is the best way to convince dealer to check for CELs? They didn't want to check in my case as no CEL was on the dash yet there was one discovered internally once they bothered to scan.
-Not clear about this but has anyone continued to have this code come up again after the reflash or did that solve the P0229 issue? :confused:

I use an Actron CP9125 OBDII Pocketscan, but this doesn't mean I'm promoting it, just letting you know what I use.

I can't answer the boost questions because I don't monitor boost.

No, having the Code P0299 come up three times can not possibly qualify under the Lemon Law because it is easily 100% corrected with a reflash. If you are driving at or near sea level under certain air pressure situations the code could repeat many times over a short period, but this does not mean that the truck is a Lemon. It only means that your truck has the minor programming glitch which needs to be fixed with a reflash.

There is no reason why the Code P0299 should occur again after the reflash because the reflash fixes the programming error. End of story.

Forgot to mention:

(a) The Check Engine Light goes out for Code P0299 at some point after the offending sea level/atmospheric pressure conditions disappear, so that is why there was no light showing when you went to the dealership.

and

(b) In case you don't yet know, the flash was not designed to increase boost pressure. It corrected a programming fault where the system divided by zero under certain altitude and air pressure conditions, particularly near sea level. This resulted in a number which the system could not process (infinity), and caused the turbo vanes to open fully instead of adjusting appropriately for air pressure and altitude. Turbo boost dropped, and a fault code was triggered.

No, having the Code P0299 come up three times can not possibly qualify under the Lemon Law because it is easily 100% corrected with a reflash.

There is no reason why the Code P0299 should occur again after the reflash because the reflash fixes the programming error. End of story.

The Check Engine Light goes out for Code P0299 at some point after the offending sea level/atmospheric pressure conditions disappear, so that is why there was no light showing when you went to the dealership.

In case you don't yet know, the flash was not designed to increase boost pressure.



1- I get that 3 occurances before a dealer has a chance to correct the problem is not LL eligible, I was refering to if the problem occured 3 times after visits to a dealer each time.

2- Kinda answers #1. True, it "SHOULD" not come on again. My question was wether it had been coming on again after the reflash or if the reflash had cured the problem once and for all for everyone.

3- No CEL ever came on in my case. That's why no light was on when I went to dealer. I was looking for peace of mind that no underlying issues remained after my earlier transmission issues. Evidentaly, my concern was valid.

4- I get that the reflash doesnt get me more than original boost target, (BTW, anyone know what factory boost target is?) I was just wondering how low the boost was during the underboost condition. Also, did this condition keep boost down continously or only momentarily while the vanes were out of intended position?

I had the reprogram done on my truck today, bulletin 11-06-04-001A, need to follow up with service advisor that the code cleared was P0299.

The CEL came on last Saturday afternoon when I was driving back from Brazoria County, south of Houston, and the mpg dropped to 12.8 mpg from middle 16's while driving 65 mph on BW8 with no load, so the theory of occurrence of this event at or below sea level makes sense.

When I saw the reduced mpg I at first thought I was in regen, but then when I shut the truck off later, high idle was still present and CEL would not go off. My CEL never went off, and so remained on until the dealer cleared the code(s).

Thanks to the great posts in this forum, I had a good idea what the true issue was before taking the truck to the dealer to get the code identified and the issue addressed.

If the def cost was $12/jug (2.5gal) it would be about right (4.95/gallon).

If the def cost was $12/jug (2.5gal) it would be about right (4.95/gallon).

It was quoted per gal. Got quoted at $15+ per gal at my local Chevy dealer who warned me against using non-GM DEF.

I don't know if they still have it on sale, but I got several 2.5 gal containers of valvoline DEF at Napa for $10.49 each. It's the best price I have seen on it.

Also, local Flying J has BlueDEF 2.5 gal for $13.99, O'Reilly's has the same for $11.99

I don't know if they still have it on sale, but I got several 2.5 gal containers of valvoline DEF at Napa for $10.49 each. It's the best price I have seen on it.

Also, local Flying J has BlueDEF 2.5 gal for $13.99, O'Reilly's has the same for $11.99

Thx

Is blue DEF the same? Are there any brands/styles to avoid?

I was just over in the LML looking around and seeing how things were going and decided to read this thread. Note to you guys with poor mileage. It has been a horribly bad winter and I plain gave up looking at the mileage on my LBZ. It must have been near low 14's maybe high 13's which for the same type of driving it was near high 16's in the summer months. Also note that at least in terms of the LBZ and driving around here in the NE fuel mileage loss is a gradual thing. Gets a little colder late october and you loose some. Gets colder yet in Dec, Jan, Feb and loose some more, real bad winter with lows consistently in single digits for a long time and plain old tanks the mileage. I'm also using Stanadyne on a consistent basis so no help there. Finally good fuel mileage is earned. I have acually adjusted my driving habits completely trying to get mileage out of my truck and it even transferred over to the two cars. Give it a little time babying the truck and getting some warmer weather and your likely to see the mileage pickup. Finally I don't know for sure but I would guess everybody gets winter fuel. I mean why to refineries try to mix two different batches screwing up their revenues? Maybe they do maybe they don't but if it concerns pennies even then they have a reason to refine only one type of fuel.

MXPOP, as long as the DEF has API certification, it is OK. Check your diesel manual and you will see the specification listed there.

Add me to the mystery turbo boost code. Every time I pull my 40" race trailer I get the CEL and boost code. By the time I finish the trip CEL is gone. This weekend on my way home from OK truck went into limp mode while driving 80 down I-40 and could have caused serious problems in heavy traffic. Cycled the key a few times and truck had power again but still had the CEL on. Drove another 500 miles and the CEL turned off. Dealer told me today that truck has no codes and nothing they can do.:mad:

Edit: I should add that I never cleared the codes and found out what the problem was from Onstar. I don't understand how the truck is not recording the CEL.

lxh0318, haven't you had the reflash yet for the boost code?

lxh0318, haven't you had the reflash yet for the boost code?
I have only had my truck for a few months and the dealer said it was already done when I got it. The only reflash due for my truck when it was there yesterday was the DEF calibration which they did.

lxh0318, haven't you had the reflash yet for the boost code?

what boost reflash r u talking about but I did not have any codes

maxx1015, for a number of months after production first began, there was a programming glitch in the controls for the turbo. It caused a temporary code situation and power loss when the truck was at or near sea level. Easily fixed with a reflash. Talk to your dealer.