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DEF problem

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The first and most obvious thing to try is to empty the DEF tank and put in fresh DEF. With milage that low it is probably the original DEF. Since the Chassis was manufactured sometime in 2022, it could easily have endured a summer with no house on it, cooking the original DEF in the tank.

A quick test is just to smell it - if it smells strongly of ammonia, the DEF is bad. For comparison, smell a new jug of DEF. Unlike your Ford, these systems are fairly fragile, and while it seems most of the kinks have been worked out, and technology is finally catching up to the mandates more than a decade later, the systems are still sensitive and require more care than you probably expect. Also a high ammonia concentration can be harmful to the electronic sensors in the tank leading to a failed DEF head.

So check the DEF, do a smell test, syphon (or drain if your’s is blessed with a drain plug) the tank, and put in a couple jugs of fresh DEF (check the date code on the jugs). This will probably solve the problem and the code(s) should clear after a few ignition cycles. If it doesn’t then yes you have bigger problems, but at least its a warranty issue, so it wont cost you anything but time, and you’ll have ruled out bad DEF.

By way of example, here’s a chart on the life expectancy of DEF at various temps:
F67D0D72-E205-4C92-B5A2-9278052FC460.jpeg

You can’t assume anyone has paid the slightest attention to the condition or age of the DEF in a new coach. Beyond reading the gauge on the dash, most dealers know nothing about the systems and don’t want to know. Your rig probably gets around 250+ mpg of DEF, and since it’s never been low, it‘s probably never even had any added to dilute the original fluid.

And as mentioned before, retrieve any codes and post them here. They are very helpful in identifying the cause or at least where to look. Also one (or more) of the codes might include a state of de-rate and you need to know if that has happened, and if so to what level of severity, before heading off on a long drive.

And as @Neal mentioned, DEF issues are a responsibility of the chassis manufacture, not Newmar. Other emission issues such as DOC/SCR/DPF are on Cummins. These emissions systems can be problematic, but once you get them sorted, and get acquainted with the system, things smooth out. Mine was a real pita in the beginning but trouble free now, and a lot of that was just me gaining an understanding of the care and feeding of the thing. All the stuff the dealers either can’t or won’t tell you. Also you would do well to invest in a decent code reader to save yourself some time and trouble as problems arise.
 
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I do keep a refractometer. I check it after the coach has been stored for 2 months or more. Our coach throws codes willy nilly. Has never derated. New Nox sensor didn't help. Now it's going in to cummins for SPN 3216 FMI4
I sure hate this DEF stuff. They say my 2014 does not have head problems. I think you will be fine but geez 41 miles! I'd be upset also. Good Luck.
Your 2014 can still have DEF head problems, but being pre-2016 you dont have a DEF quality sensor which has been the cause of the bulk of the DEF head failures.

On yours its usually an incorrect level reading. It has a mechanical float for the DEF gauge, and DEF tends to precipitate out dry crusty gunk that crystalizes and causes the float to hang up. This is the TSB on that issue: https://static.nhtsa.gov/odi/tsbs/2013/MC-10142383-9999.pdf

But, as you probably already know, SPN 3216 is a NOx code and FMI 4 is low voltage condition or a short, so if you had a new NOx sensor installed and still have a problem, they didn’t fix it the first time, and it could be in the wiring harness, or some mysterious electronic issue.
 
Can anyone chime in here that has ever found their DEF fluid to be the cause of any of these problems? I believe Spartan will tell you to drain the tank, soak in a vinegar solution for 24-48 hours and refill with DEF but I don't know that it's ever solved the problem other than replacing the DEF head. I'm just curious to track some statistics on problems and solutions as well as document failures.
 
Can anyone chime in here that has ever found their DEF fluid to be the cause of any of these problems? I believe Spartan will tell you to drain the tank, soak in a vinegar solution for 24-48 hours and refill with DEF but I don't know that it's ever solved the problem other than replacing the DEF head. I'm just curious to track some statistics on problems and solutions as well as document failures.
I’ve read many accounts of “bad DEF” causing fault codes and leading bad DEF headers and derate, but there are two very different conditions resulting from old/bad DEF.

One is detailed in the TSA bulletin noted above for pre-2016 mechanical float DEF heads and it can sometimes be resolved by cleaning/rinsing the DEF header with distilled water, vinegar, new DEF, etc, sometimes without removing the DEF header.

Mine was still under warranty when it sent errant DEF level codes (causing derate) so they just replaced the DEF head (DEF header in Freightliner lingo), twice! But I now suspect the DEF header could have been saved, and I could have avoided the lengthy stays at the FL shop. Maybe it could have been resolved by rinsing, cleaning, etc, but I was new to the whole DEF debacle then and just took it to a shop. Also the coach was under five years old so still under the emissions warranty.

The other occurs when an excessively high concentration of ammonia corrodes and destroys the electronics, usualy in the solid state “quality sensor”, (2016 and later DEF heads) and that one is a lost cause requiring DEF head replacement. This has been more common in Spartan DEF heads, but FL has had their share too. Both seemed to have resolved the problem for the most part with improved DEF heads, Spartan being at least on Gen 7!

From the description, it sounds like right now @team bradfield has a DEF header that’s working and the quality sensor is doing its job warning of overly concentrated (high ammonia content) DEF. If this is the case, just changing the DEF will resolve the problem and the codes will clear after a few ignition cycles.

If the problem persists then its probably a bad sensor and the DEF head needs to be replaced, but typically that causes the “big three” codes: SPN 3364, 1761, 3031, quality, level, and temp. In his case it appears that its just reading a DEF quality problem (probably SPN 3364) and if so new DEF should resolve it. I’d like to see the current codes in this case.
 
waiting for a call back from spartan, I've put less than 40 miles on this rig
The good news is that it wont derate in 40 miles so if you are that close to the dealer, you can drive it there and let them deal with it.
 
I'm hoping to hear a good outcome for @team bradfield and great experiences ahead as I love my Newmar and hope they will as well.

As to the ammonia situation you think the tank needs to be vented or we should even store them with the cap off. It's as if they are not accounting for gassing.
 
My understanding is that the ammonia is in solution where high levels cause the corrosion. Heat releases the ammonia (needed to react with NOx) so I think the key is limiting heat exposure to your DEF tank (and stored DEF), and if it sits over a period of time exposed to higher temps, replace it based on the chart above.

I enclosed my DEF tank compartment, but I haven’t insulated it (maybe I should) so I can’t say if it has helped or not. It did give me more storage though. I have also dumped and replaced my DEF when it smelled strongly of ammonia (much more so than ‘fresh” DEF) but this was a precaution back when I still thought I had a “quality” sensor (my 2016 is on a 2015 chassis) and I don’t know if it was necessary or helpful.

I’m also anxiously awaiting the codes and outcome of @team bradfield ’s dilemma.
 
thanks to all for the input, under a winter storm warning right now, coming down pretty good, probably on hold until Saturday, calling for 8-10 inches, tomorrow will be snow blowing day
 
So in team bradfield’s situation would the DSS device work if he were to go into derate mode?My 2018 Essex is now showing a 4331-16 HIGH code.Spartan is saying it’s a problem with the Dossing unit.Incorrect quantity. Is this something that could put me in derate?
 

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