Crystalized DEF after setting 5 Months

[Rich W.]

Such great info from all that answered. Thank You
Freightliner took my friends Ventana LE into the shop about 2pm today.
Will post the outcome once I hear from them.
I purchased a Refractometer on Amazon today. Arrives sometime tomorrow.
Following you'all's advice I will test what's been in my tank these last 3 months and go from there.
More later.
Thanks Again

It will be interesting to hear the results. What year is his coach? Hopefully they will be able to remove, clean and reinstall his existing DEF header (as per the TSB, if thats the problem) and be done with it.

One of the problems Ive encountered is techs guessing their way through these problems and performing tasks, such as forced regen, that are unrelated and do not address the problem. But they rack up the hours in the process.

I had mine in three times for emissions problems while under warranty, and the previous owner had the DEF header replaced as well. Once my emissions warranty ended I made it my mission to bettrer understand the system so that I wont be at the mercy or incompetent or unscrupulous shops. I also use a refractometer but have never seen a reading that would indicate bad DEF.

I also will only go to an approved Freighter shop, but will do everything I can to avoid that, and will boycott Cummins shops if at all possible. Lessons learned….there’s more but I’ll save it for another day.

 

[bowpulpit]

One of the problems Ive encountered is techs guessing their way through these problems and performing tasks, such as forced regen, that are unrelated and do not address the problem. But they rack up the hours in the process.

The saga continues.....
My friends called about 2 hours ago very happy as they were out of Freightliner and on their way from El Paso to Van Horne. I asked what the fix was and they said the Tech did a "forced regen"!
Well....about 15 minutes ago well on their way they called me and said ALL lights were back on! They have not derated and keeping their fingers crossed they can make it to Van Horne for the night and determine next steps tomorrow.
I had just finished reading your post Rich W when they called.

 

[Rich W.]

The saga continues.....
My friends called about 2 hours ago very happy as they were out of Freightliner and on their way from El Paso to Van Horne. I asked what the fix was and they said the Tech did a "forced regen"!
Well....about 15 minutes ago well on their way they called me and said ALL lights were back on! They have not derated and keeping their fingers crossed they can make it to Van Horne for the night and determine next steps tomorrow.
I had just finished reading your post Rich W when they called.

This is one of the problems we face. All regens, passive, active, and manual (aka parked or forced), happen in the DPF in an effort to burn off soot to keep the filter clear, active and manual occuring with the benefit of increased heat provided by injecting diesel into the exhaust.

DEF is injected in the SCR where urea, under high heat, converts to ammonia which in turn through a chemical reaction converts NOX (nitrogen oxide) into nitrogen and oxygen (air).

Thats all great (when it works) but it all happens AFTER the DPF and is completely unrelated to the soot filter which is cleaned by performing regens. But in my experience its the first thing a tech will do as a “rule out”.

Below is schematic of the sysstem: DOC, DPF, then SCR. So you can see that if you have a DEF problem, no efforts to change things in the DPF will address the issue.

Im sure the tech cleared the codes and reset the emissions sensing stuff, which got the owner out of the shop and down the road a ways, but did nothing to address the DEF issue, which is undoutably a faulty senssor, whether in need of cleaning or replacing. Once the sensors detected the problem for a long enough period, the codes came back.

Eventually he will be derated in three stages (see 2,3, and 4 in the second chart). He may not notice the first stage (25%) unless he’s towing and/or climbing grades. It would be interesting to see the codes he is getting on the LBCU. Reading the codes will also help him estimate how far he can drive before the final stage of derate restricting him to 5mph.

In the mean time he should not shut off the engine (limit ignition cycles as the ECM apparently counts them) or get fuel unless absolutely necessary, as these things accelerate the derate process.

Here’s a couple of other items to consider when you have DEF related codes and warning lights:
1 If check engine and the other s DEF lights are on and you fill your fuel tank you will be you will be derated right away.
2 If you idle the engine for more then 1 hour with the same lights as above you will also be derated.

Ive also read that you can get fuel as long as you dont add more than 20 gallons. Some of this is from qualitifed sources, some is anecdotal, and some is probably guess work. But this is the only hope of delaying a full derate.

I would have turned around and headed back to El Paso (Im sure its too late now) since its 120 miles to Van Horn, and to my knowledge there are no resources there that can help. Eventually he will derate. I wouldn't drive any more than absolutely necessary as it is impossible to determine exactly when the final stafe of derate will occur.

 

[Rich W.]

The saga continues.....
My friends called about 2 hours ago very happy as they were out of Freightliner and on their way from El Paso to Van Horne. I asked what the fix was and they said the Tech did a "forced regen"!
Well....about 15 minutes ago well on their way they called me and said ALL lights were back on! They have not derated and keeping their fingers crossed they can make it to Van Horne for the night and determine next steps tomorrow.
I had just finished reading your post Rich W when they called.

PM sent, and not to overwhelm, but of its just a Low DEF code, its probably the tank level sensor and servicable. If its the “dreaded three” it’s a DEF header failure and will require replacement.

Also if his chassis has pre-2016 emissions, it will not have the quality sensor (thankfully) and the level sensor will be mechanical and possibly serviceable. Also if coach is under five years old and 100k miles, all of this is under the emissions warranty.

The three:
1761 – Diesel Exhaust Fluid Tank Volume
3031 – Diesel Exhaust Fluid Tank Temperature
3364 – Diesel Exhaust Fluid Quality

There may be other codes involved as well. Hopefully he can operate his LBCU. If not instructions are readily available.

 

[Rich W.]

This is a page from OTR diagnostics for fault code 3547 (DEF tank empty). He may not have this code but this image shows the drive times before derate. But the thing to remember is that derate is also affected by the conditions listed in post 18. So its a crap shoot and I wouldnt rely on 40 hours of drive time.

 

[FL-JOE]

Believe it or not, but many Cummins/Freightliner Service centers will reset these engine codes when they have to do with the DP's DEF tank or DEF system and put you back on the road. Two of them did that to me, telling me that it was probably just a "ghost" engine light and would probably never come on again. The whole time it was a failed DEF tower/head. The third time it came on I was in Florida. North Trails in Ft. Myers checked it and knew immediately what it was. Two hours later it was replaced and fixed for good.

Very common that these DEF tower/heads are still going out. Back when North Trail replaced mine they said they were doing at least one or two a week.

As far as DEF aging out, just apply common sense. Just think about the hundreds of thousands of DP's that are sitting for 3 to 6 months in Florida. Are there now a bunch of them sitting on the shoulder of I-75 and I-95 with failed DEF systems? Of course not. You can leave your DP sit with DEF in the tank for several months as long as the DEF wasn't 10 or 12 months old when you initially put it in there.

 

[bowpulpit]

Rich W.....you have been stellar with your responces and info. It is appreciated. I've passed all your posts along as well as your phone number. My freinds name is Bill Hunt in case he calls you.
Steve

 

[Rich W.]

Sounds good. I was looking around the West Texas neighborhood and the next decent choice for service would be Odessa, but that‘s 40 miles more driving than El Paso.

I just traveled through there, and Van Horn (before and after my winter Gulf Coast tour) and Odessa immediately came to mind as there is so much going on there, I figured there had to be good services. So I checked and there is a Freightliner dealer.

Still curious about the Coach model, year, and his current codes. Hope he makes it where he’s going - its pretty stressful driving long distances (or anywhere really) with codes that could lead to derate, and one of my primary goals is to avoid being towed.

 

[DHudson]

With all the issues I hear about DEF, I only stock a little more than we usually sell in a month. The city approached me about selling them in bulk. After figuring out how much they used a month, we all decided that they would be better off buying by the box. One failure from bad DEF would wipe out many times over the savings they would get buying in bulk.

 

[Old-RV'er]

All- This subject is batted around here numerous times. As stated above, DEF has a shelf life. To prevent this, move coach about once month, taking a 25-mile one way trip and back, this will help keep everything free of moisture, get all the lubricants moving where they should be, etc. It will use some DEF, that means check its level, but don't let the thing sit for a long time and not use it, machinery is designed to be used, not to sit. Keeping the tank full will help to avoid this, but again, it's not a guarantee. Driving it for several hundred miles "out with the old and you will put in the new"