Re-Flash Recall Bad News

[moss6]

If you are not having DEF or regen problems with your LML and have not had it reflashed, DON'T I repeat DON'T. This reflash amoung other things reverts back to injecting additional fuel to the cylinders (like the previous regening models) in addition to the #9 injector in the down pipe. GM has explained that the EPA has been finding some LML's exceeding the current emission levels in vehicals already placed in service and have mandated additional measures be taken to insure those levels are not exceeded. It is my understanding that California vehicals must comply with the recall in order to renew registration whether the vehical passes inspection or not, but I have not heard of this requirement for other states.

This reflash cannot be reversed due to the fact that the original cannot be recaptured. My truck has been compromised due to big brother EPA incroachment and I am stuck with it now with no recourse. Had I known I would have never brought it in voluntarily. With what I am seeing now non towing the EGT's when pulling hard are going to be in the 1700 degree range.

Don't make the same mistake.

[More Power]

Hmmm....

There are two primary emissions of interest in diesel exhaust: NOx and PM

PM (Particulate Matter) is the soot we see. NOx is a smog forming pollutant, and is produced in a direct relationship to combustion temperatures. As combustion temps rise, so does NOx. Running cooler reduces NOx.

Doesn't make sense that GM would alter programming to add fuel to all eight injectors unless they are doing it to reduce NOx formation after the combustion event, with the exhaust valves open. Can't add fuel during a combustion event.

Adding fuel to the exhaust stream will also raise temperatures in the DOC (Diesel Oxidation Converter - aka catalytic converter) and exhaust particulate filter.

Back a few years ago, Dodge did about the same thing with their Bosch VP-44 equipped Cummins trucks. Called in all the owners of the new trucks for a reprogram, and whammo.... there went 2-3 mpg and less power.

Manufacturers should be required to "do no harm" with any emissions pregram update. Less power and fuel economy after-the-fact reduces value already paid for.

Jim

[moss6]

We must remember the EPA has absolutely no empathy for the consummer; that is unless the consummer wants an all electric vehical. They also really care not, that we waste fuel, or that their idiotic mandates may actually increase consumption; only that that wasted fuel does not exceed their near zero level emissions standards. We must also remember that nothing they have ever done has had even a sembelance of common sense to it; what would we do without them, I suspect the world would be lost by now.

[Jeff22]

Couldnt agree more. It totally amazes me that our modern day vehicles are much less fuel efficiant than the vehicles we had 40 years ago. Burn more fuel and produce less emissions?

[Mark Rinker]

Thanks for the information. I will steer clear of any updates!

My 2009 LMM is bone stock in all regards, mileage has improved since I bought it with 15K miles - it now has about 70K miles and outperforms the previous two 2006 LBZ Duramaxes I've owned in the following ways:

Mileage (loaded and unloaded)
Heat rejection (never had an issue - water or trans)I was concerned at first at the amount of fuel used at regen. If the truck is regenning at this point, it is imperceptible or lost in the averages. Loaded and unloaded (empty 3K trailer) mileage is in the 11-12mpg range for the entire season, where the LBZ doing the same work would have been in the 10-11mpg range.

[cowboywildbill]

I would like to see the actual data that shows the fuel issue. I had our LML reflashed a month ago and then had a regen "which was due" take place. I noticed that my regen average mpg was better than previous mpg during regen ? Also my empty mpg is the same as before the reflash, and that is better than our LBZ was getting. So I wonder what the reflash really does. From my experiance it doesn't affect mpg.
If the info about the flashes is comming from a simular forum, I wouldn't jump to any conclusions about what is really going on. Maybe someone from GM can actually tell us what exactly the latest def reflash really changes.

[moss6]

I would like to see the actual data that shows the fuel issue. I had our LML reflashed a month ago and then had a regen "which was due" take place. I noticed that my regen average mpg was better than previous mpg during regen ? Also my empty mpg is the same as before the reflash, and that is better than our LBZ was getting. So I wonder what the reflash really does. From my experiance it doesn't affect mpg.
If the info about the flashes is comming from a simular forum, I wouldn't jump to any conclusions about what is really going on. Maybe someone from GM can actually tell us what exactly the latest def reflash really changes.

Actual data; yeah me too! And no, not from another forum, but my hypothosis based on what I saw after the reflash. As for for your LBZ, sorry it must not have been a good example of the generation as our old LBZ towed with a good bit better mileage than the LML. LML does outpull by a little bit however.
After a 1500 mile towing trip, getting back this evening, I find some other things that the re-flash must have screwed up.

Now the fuel used shows about 1 gal less than what it takes to fill the tank after about 24 gals used. Before it was always within a tenth which could easily be topping difference. Used to be quite confident in planning fuels stops if I wanted to cut it close; not no more as I cannot trust it.

Computer mpg now consistently shows 1mpg better than actual hand calc.; it was always spot on before as was the LBZ's.

The positive this trip was the high EGT's, which I was afraid might be unmanageable if in re-gen did not occur. In 1500 miles I would have though that I would have had at least one re-gen but I never got any indecation of one. Also something that was really pleasing and not at all expected was that the highest EGT's I experienced over the passes never got to 1400 degrees. That is a first and even less that with the old LBZ same speeds and same loads but the ambient was more favorable than any other time than I can remember. The LML may be breaking in nicely? Dunno, seemed to pull them easier-----cooler=power, so---?

[Mark Rinker]

I try not to look at individual loads or trips. Too many variables, including wind direction, temperatures, grade, etc.

Last years 50K mile average is significantly better, load/unloaded with trailer/empty truck/snowplowing than either of the LBZ.

Significantly so. To the point that I pay no attention to the regens, and would not consider messing with replacing the exhaust and/or reprogramming the EMC.

1) As long as all these activities averages out to 11-12mpg - 2) the check engine light stays off - 3) the truck continues to pull like a banshee, well...business can't be better.


LIKE A ROCK!!!

[moss6]

[QUOTE=Mark Rinker;285065]I try not to look at individual loads or trips. Too many variables, including wind direction, temperatures, grade, etc.

Last years 50K mile average is significantly better, load/unloaded with trailer/empty truck/snowplowing than either of the LBZ.

Significantly so. To the point that I pay no attention to the regens, and would not consider messing with replacing the exhaust and/or reprogramming the EMC.

1) As long as all these activities averages out to 11-12mpg - 2) the check engine light stays off - 3) the truck continues to pull like a banshee, well...business can't be better.

Mark,
Like I stated these were the best conditions I have towed in over the majority of the route that I take at least two times a year. Even with that I can't help but be surprised that the EGT's were so in control and near the end of Raton pass going south I was about 5mph faster than normal (60 mph in 4th). I am just at a loss as to why they screwed with other parameters and messed them up. I love the EPA/GM connection; noticed in the GOP debate Thur. that some of the want to be's share my sentiment.

[Mark Rinker]

I am not in favor of the EPA running amok, costing consumers unmeasured dollars to return unquantified returns in air quality. Where I live - there is no air quality problem. i.e. Why should I lose efficiency in MN to benefit CA?

However, I have come to terms with the current DPF system. In fact, its quite amazing to see a diesel truck that makes this much power, that simply does not emit any black smoke. Ever.

Start my 2003 TDI on any given day, and our culdesac stinks of unburned diesel until the engine warms up. Can't be healthy to breathe unburned fuel hanging in the air - a known carcinogen.

Somewhere in the middle of tree hugging stupidity, and environment diminishing pollution, there must be a rational approach to preserving our planet while harvesting, and managing its resources.

Why we can't seem to find that balance - I don't know.

[moss6]

Xactly; maybe we are at the point that the American public has realized the harm rather than good the EPA among other Fed. wasteful entities is doing to our countries economy and overall well being. Never in my lifetime have I seen the overt public challenge to big government ignorance and squandering of the taxpayers hard earned dollars as what we are seeing with the current contingent of presidential hopefuls in the GOP. We can only hope that they are indeed sincere and willing to back up their words with action if elected. I prey that this is not wistful thinking.
I see how good the current crop of pullers is and wonder how much better; efficient and clean, they could be without the Feds unrelentless interference. Case in point, the current EPA mandated GM programming that apparently is a coerced bust to appease the EPA. I'm sure those misguided do gooders are well pleased with the exercizing of their power over an Icon American manufacturing corporation. I hope that light I see is the end of the tunnel.