Nox Nox, Who's There (How Many Sensors Fail?)

[Oldforester]

I have a 2015 Interstate GT with 28K miles, exactly 2 years old this week. Today, I have taken it back to Mercedes for the 4th time for a check engine light, linked to the NOX Sensors. So far I have had three replaced, and am assuming today will be the 4th.

I've read previous Forum posts and understand that the problem is common, but how common, and is there a reason? In reviewing the "chart notes" of my vehicles trips to the Mercedes ER I saw the following quote, and have attached it as well. The tech noted: "this unit is an upfitted motorhome so the exhaust is different which may effect how long the replacement of the component takes"

Is it possible that the aftermarket changes Airstream makes to the exhaust has an effect on the NOX sensors shortening their longevity? As noted by others, once out of warranty, these changes are going to cost $1,000 per episode.

PS: Having these sensors go out and starting a countdown clock telling me I have 16 starts to get it fixed until the unit shuts down completely is more than annoying. Especially when I am sitting next to a feedlot in Nebraska with enough methane in the air to fuel half of California.

[toskeysam]

Not sure what to say. Equipment installed in unfit can be "in the way" sometimes, and can lead to more labor in swapping sensors out. Mine were swapped without comment, except that their computer kept crashing when they went to reset the system.

[toskeysam]

Dang autocorrect....meant "upfit" not "unfit".....although there may be a bit of humor in that.

[LB_3]

Get your ECU reprogrammed. Some of the tunes will ignore emissions sensor errors.

[73shark]

I was told when they replaced both of mine ($1,500) that MB had a software problem w/ the sensor heaters causing them to fail prematurely. They couldn't tell me if they had the SW fixed or not.

[VAtom]

This is a sad state of affairs.

So, the complex system fails way too often, (twice for me) but the real problem is that the EPA requires the manufacturer to disable the vehicle for no good reason. (RV suicide)

Imagine the planet-wide horror of ten dozen Sprinters roaming around Montana and South Dakota with perfectly functioning NOx exhaust treatment systems but faulty $1000 sensors.

Seems like overreach.

[dcasr]

Originally Posted by VAtom

This is a sad state of affairs.

So, the complex system fails way too often, (twice for me) but the real problem is that the EPA requires the manufacturer to disable the vehicle for no good reason. (RV suicide)

Imagine the planet-wide horror of ten dozen Sprinters roaming around Montana and South Dakota with perfectly functioning NOx exhaust treatment systems but faulty $1000 sensors.

Seems like overreach.

________________________

Seems like VW/Audi should have a computer fix for this; they are experts at computer SW to fool the federal standards. There is definitely a need for a computer SW reprogram that will ignore the shutdown phase of the the algorithm.

[Isuzusweet]

Here's my take on this, and other modern day diesel emissions problems......keep taking your vehicle back to MB to have all these sensors fix while under warranty; the very second the warranty is up, take it to your local VW dealer for "recalibration" and "parts reallocation".

I wouldn't buy a modern diesel if my life depended on it......come to think of it, if I had a heart attack I'd tell them to bring a gas powered ambulance.

Cheers
Tony

[VAtom]

[QUOTE=Isuzusweet;1923457......come to think of it, if I had a heart attack I'd tell them to bring a gas powered ambulance.
Cheers
Tony[/QUOTE]

I actually rode toes up in a Sprinter ambulance. What a rough rough ride. Way worse than my AI.

The EMT said they really needed the air bag suspension system.

[busb2]

Reading about all the NOx issues I don't understand why I have never had a single issue. I have owned two AI units, currently have a 2014.5 and a 2011 before this one. At the same time, my wife is on her second MB 350 GL starting with a 2009 and now a 2016. They have the same engine as the Sprinter and we have never had a NOx issue with any of these in over 125000 miles of combined use. Just good luck, or is there some other variable at play, like fuel variations, climate, driving habits? Who knows.

[Doug Odom]

Read this article ref "The Fatal Flaw of Mercedes Benz Sprinters".
I've had two replacements in 19K.
https://www.linkedin.com/pulse/fatal...-tom-robertson

[amirm]

When I took my 2016 (built in 2015) to MB they changed emissions settings in the ECU. Seems like it is still work in progress and we are test subjects!

[Oldforester]

Started this thread, and thanks to all the contributions especially the article mentioned by D.O., the link here:

http://www.linkedin.com/pulse/fatal-...-tom-robertson

After reading that article of an owner of a fleet of Sprinters, and others through a Google search, it appears when independent service centers and owners of commercial Sprinter fleets have concern based on high volume of sensor failures using their own statistical records, there is certainly smoke, if not fire.

After discussing this with my local MB dealer and MB corporate this does not appear to be an Airstream generated issue, but related to the complexity of the emission system which changed in 2008 as a requirement to meet federal emission standards.

There is a bit of good news. If you live in certain states, in addition to your powertrain warranty, and 3 yr 36,000 mile bumper to bumper warranty there is another warranty (in the case of my 2015 Sprinter) called the California Emission Warranty which in addition to California also covers the states of Connecticut, Delaware, Massachusetts, New Jersey, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington. You can find this in your MB warranty information, it was never mentioned to me by any of the MB service centers or AS. Specifically covering the emission control system, it provides a 5 year, 100,000 mile warranty on most emission issues, with a separate area covering items for 7 years from date of purchase. Have attempted to attach a PDF for the 2015 model that explains the coverage. Might be worth looking into for other states and model years.

An item which surfaced was the topic of fuel contamination. At times MB denies warranty coverage for emission system failure due to "fuel contamination." I am not a qualified technician, but if you have a complex system that is monitoring several sensors, a catalytic convertor, pressure pre and post convertor, plus multiple Nox sensors, and others it seems likely you are playing bad odds using anything less than the best fuel in these engines.
And hope the attendants are filling the station tanks properly.

Finally, the more I learn about the Nox sensor "countdown clock" the more irritated I become. When the Nox sensor fails, the display tells you initially that you have up to 16 restarts before the vehicle is totally disabled. But, I learned that that number can drastically change, and not go chronologically down, but can skip to 5 or 6 starts, for instance, before being disabled. All this based on a computer algorithm monitoring multiple factors, ie. miles driven, temperature, fuel consumption, etc.. This is extreme overreach. You could be stuck with your family miles from service with an inoperable vehicle, that could run perfectly fine, but is shut down because it is a pollution risk? Why didn't they set the system up using time as a factor rather than variable restarts? You have 15 days to repair the system before loss of use for instance? Time for a cocktail Safe driving to everyone!!

[amirm]

That's great info for those of us who live on the west coast. Thanks for posting it Oldforester!

[LB_3]

The day it's out of warranty get an off-road tune and never buy DEF again.

[dcasr]

Originally Posted by LB_3

The day it's out of warranty get an off-road tune and never buy DEF again.

__________________
OK I've got a 2016 Duramax that has a 60 month bumper to bumper warranty. June of 2021 I'll be off warranty. How do I get an off-road tune that will by pass all of the equipment, sensors, etc that they have put on it?

I bought one of those re-tune kits and re-programmed my 1999 7.4 gas Suburban last year and it worked great for six months, then the on board computer had a fatal crash. I re-tuned it to original specs but the on board computer was really dead. I'm a little leery of those re-program gadgets, so explain more specifically, off line if necessary, how this is done. Thanks.

[LB_3]

We luckily don't have this worry with our T1N so my research is limited. RennTech may be the most reputable tuner but they no longer offers the emissions deletes. ProTag even had his dealer install the RennTech modified ECU. Other vendors like Malone Tuning have you sign an off-road waiver but I can't vouch for them (or any other NCV3 tuners.)

I've read on other forums that some tunes can eliminate the X number of start countdown when flags are thrown without actually changing performance or emissions. And of course removing the speed governor is popular with some drivers.