DEF problem

[mansracing]

Rich W you suggested buying a code reader do you have any suggestions on which one?Can they also reset codes?Just trying to learn more about the Def system.

 

[Rich W.]

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?

Yes the DSS would send a “all sensors normal” message to the ECM, but it wouldn’t be a good idea in this case because his DEF head is probably working, indicating he has an DEF actual problem. The DSS is better suited to dealing with false readings, such as low DEF when you know the tank is full. Bypassing the DEF header when there is an actual problem doesn’t fix anything and might make things worse.

In your case, Spartan (or cummins) is the best one to answer the derate question. SPN 4331 is “Aftertreatment 1 Diesel Exhaust Fluid Actual Dosing Quantity“ and FMI 16 is reading “high“, so it shouldn’t lead to derate because the only issue is that you’ll consume more DEF than necessary, but you’ll want to read all codes to make sure. If you are in initial derate you’ll see SPN 1569.

Also if your check engine light is on and has a wrench in it, you are headed for, or in the early stages of derate. If it starts flashing you’re in a more severe level of derate. And the DSS wouldn’t help you here because the error message isn’t originating in the DEF head.

Since your coach is a 2018, this is the last year of your emissions warranty, so I’d check your delivery date and if you are still under five years, get it in and get it fixed.

 

[Rich W.]

Rich W you suggested buying a code reader do you have any suggestions on which one?Can they also reset codes?Just trying to learn more about the Def system.

There are a lot of cheap J1939 code readers that work, and many will clear codes after the problem has been corrected, but after trying several, including OTR which is great but requires an annual subscription, I’ve landed on this one as ideal for the coach owner:

Used Diesel Laptops Handheld Heavy-Duty Scan Tool with Regen

Please Note: This kit is used and is in good condition. The Diesel Handheld scanner is very simple to use. This handheld is specifically designed for the heavy-duty market. It allows reading and clearing of DTC's, Live data reading, and even DPF regens on most makes and models. This tool comes...

www.diesellaptops.com

This is a great deal - half price, and they don’t always have used units available. I bought mine used and couldn't tell it from new. Also their customer service/tech support is outstanding. But you can also retrieve codes from your dash, and there are numerous cheaper J1939 code readers on Amazon.

 

[mansracing]

Is the only time you would use the DSS device if there is a problem with the def head?Deff sensor or fluid level?
Thanks for all your help and info.
Randy

 

[Rich W.]

Is the only time you would use the DSS device if there is a problem with the def head?Deff sensor or fluid level?
Thanks for all your help and info.
Randy

Yes. In the event of a DEF head failure, when all else is working fine, the DSS sends a simulated “all is well” message for the three sensors (level, qual, temp) to the ECM. It will only work on a 2016 or later chassis.

The most common failures occur with three codes indicating problems with all three parameters at once - an obvious DEF head failure. So the DSS simulates a healthy DEF head and sends the correct signals preventing a derate, and if all ready in derate, the ECM senses the problem has been solved so after about 5 or 6 ignition cycles usually clears derate and codes.

This allows the owner to still operate the vehicle until such time as a new header is available and an apointment can be scheduled to have the work done - both of which have often been a very long wait. The only caution is that you still have to put in DEF and you no longer have a working level gauge, so you have to be diligent about keeping the tank full, or you’ll have other problems, such as a 4331 18 (doser out of spec - low) which will cause a derate and the DSS cant do anything about it.

This is the DSS home page: DEF Sensor Simulator

 

[DennisT]

There are a lot of cheap J1939 code readers that work, and many will clear codes after the problem has been corrected, but after trying several, including OTR which is great but requires an annual subscription, I’ve landed on this one as ideal for the coach owner:

Used Diesel Laptops Handheld Heavy-Duty Scan Tool with Regen

Please Note: This kit is used and is in good condition. The Diesel Handheld scanner is very simple to use. This handheld is specifically designed for the heavy-duty market. It allows reading and clearing of DTC's, Live data reading, and even DPF regens on most makes and models. This tool comes...

www.diesellaptops.com

This is a great deal - half price, and they don’t always have used units available. I bought mine used and couldn't tell it from new. Also their customer service/tech support is outstanding. But you can also retrieve codes from your dash, and there are numerous cheaper J1939 code readers on Amazon.

Picked up this one recently when they had a 20% coupon sale. Figured I’d get one now before I need it on the road somewhere

Heavy Duty Truck Code Reader with DPF Regen

Amazing deals on this Truck Code Reader W/ Dpf Regen at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Tested on a coach across from us to verify they didn’t have any codes causing concern before they headed to FL for their appt.

Does force regen and also checks the ABS which I guess some of them do not do.

Worked well so far.

 

[ARD]

I had to have my DEF head replaced within 6 months of having my 2022 LA. Sorry to hear you are not getting an immediate response from Spartan. I found them very responsive, overnighting the DEF head and scheduling a mobile tech through CoachNet to have it installed.

I did get a stop engine code though. What codes are you throwing? Make sure your DEF tank is full if you are in cold, snowy weather.

 

[team bradfield]

Gremlins I guess, tested the DEF and it tests good, started her up and the warning is gone, went through the diagnostics and it doesn't show any codes, as soon as the pile of snow in front of the bus is gone, gonna take it for a drive

 

[DennisT]

Well that is good. If you are like me, you probably hate it when things just “clear up” and you don’t know why

 

[team bradfield]

Well that is good. If you are like me, you probably hate it when things just “clear up” and you don’t know why

Yep, exactly, now I'm afraid it will pop up again traveling through the mountains this spring

 

[Dutch Star Don]

It seems that most of the reported DEF head issues that flooded the forums have disappeared. The majority of the issues were with the Shaw head used on the Spartan chassis. It was also used on the Tiffin chassis. There were very few reports of a Freightliner having an issue. Back during the height of Covid and no quick repairs for DEF head failures, I actually bought my own DEF head and stored it in the coach before a month-long trip.'

Later, I made one of the DEF defeat modules. Mine will fit a Freightliner or Spartan chassis. Now, the government is allowing the bypassing of the DEF system in an emergency and DEF heads are more readily available.

To answer Neal's question, I've never seen a report where DEF fluid was the actual issue. I buy my DEF at Walmart and just add as needed. We don't burn enough DEF to deal with buying it at the pump. We rarely use truck stops for fuel, Th only issue with store bought DEF, especially at Walmart, someone could buy a jug, use it and then return it with water. Whenever I'm suspicious, I use a refractometer to check it.

 

[Richpatty]

Great thread…. I read with interest since as I also debate whether to:
- only fill DEF when needed since we don’t drive as much in the last few years (avg 2,000 miles per year) so it is always fresh.
- or keep it full so it does create any crystallization (or whatever it may do). But then the DEF will get old…especially in the heat.

I figure a happy medium would be to fill it at the beginning (or end) of the season and then drain it at the end of the season (or one year mark) and refill. This way, it would be fresh and full (at least most of the time). But I would probably end up dumping 5 or 6 gallons of DEF each year. Seems like a waste of money…

Thoughts?

As far as the Box vs Pump debate, although I have used pumps a few years ago, I have not since 1999, mostly due to the lack of long distance travels.

 

[Rich W.]

Great thread…. I read with interest since as I also debate whether to:
- only fill DEF when needed since we don’t drive as much in the last few years (avg 2,000 miles per year) so it is always fresh.
- or keep it full so it does create any crystallization (or whatever it may do). But then the DEF will get old…especially in the heat.

I figure a happy medium would be to fill it at the beginning (or end) of the season and then drain it at the end of the season (or one year mark) and refill. This way, it would be fresh and full (at least most of the time). But I would probably end up dumping 5 or 6 gallons of DEF each year. Seems like a waste of money…

Thoughts?

As far as the Box vs Pump debate, although I have used pumps a few years ago, I have not since 1999, mostly due to the lack of long distance travels.

An option is to drain the tank and fill it with distilled water for storage, then dump that and fill with fresh DEF for travel. Just dont forget and drive off with a tank full of water or you’ll quickly start throwing codes and be on the road to derate.

 

[Richpatty]

An option is to drain the tank and fill it with distilled water for storage, then dump that and fill with fresh DEF for travel. Just dont forget and drive off with a tank full of water or you’ll quickly start throwing codes and be on the road to derate.

Interesting thought...although since we store it a home, we do take it for a 50 mile drive every 30 days to give it a run and also run the generator, heat and other items so they stay exercised....so filling it with water would work for us.

Thanks!

 

[DavidL]

An option is to drain the tank and fill it with distilled water for storage, then dump that and fill with fresh DEF for travel. Just dont forget and drive off with a tank full of water or you’ll quickly start throwing codes and be on the road to derate.

And I assume that is for non freezing weather storage?

 

[Rich W.]

And I assume that is for non freezing weather storage?

yeah - storing in sub freezing temps isn't part of my reality so those ramifications don’t occur to me. I’ve never even winterized an RV. You wouldn't want a block of ice in your DEF tank and DEF doesn't start to freeze until 12°F so DEF would be better in the tank for low temp storage. And DEF wont go bad at low temps either, so the distilled water thing would only apply to areas where temps would be higher. And in those areas people probably don’t store there rigs anyway so on reflection this probably wasn’t a very useful suggestion. Time for cup of coffee…..