Another Cascadia comes in with SCR closed loop control at maximum limit SPN 520372 FMI 16
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- Опубликовано: 30 дек 2023
- I really hate this fault code, SCR closed loop can come up for many different reasons and it is important to know what to look for.
Start with looking at all the fault codes, begin a parked regen and monitor the temperatures, the pressures and the efficiency. Once the regen is completed successfully and there are no fault codes that become active. Immediately go into a parked SCR efficiency test and monitor the LARMF compensation.
The efficiency test is pass or fail, so you have to let the test start and finish on its own. Even if the fault codes are inactive during the process do NOT end the test early. 
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Muchas gracias su vídeo me salvo de ir al dealer mi troke me aventó las tres check engine lights
Great video sir!!! It helps me a lot. Thanks for sharing... god bless..
Thanks! Great video! Do you have a chart with normal values where we could donwload a Pdf and print it out. So we could folllow the paper chart and see normal vaules for SCR DPF parameters. Could you please share it? Thanks again.
Always clean the def dozer
Hey, Carlos great video. I have a Cascadia 2018 dd13 . I only have the code 520372 16 and no other codes are coming out and the hole where the def doser goes is getting clogged with crystalized def. Two months ago a mechanic did a acm update and change to a new def dozer and still getting the code 520372 16 and the hole is still getting plugged with crystalized def after driving around 30 miles. A week ago another mechanic did an csr efficiency test and pass, the nox conversion efficiency came to .098 but forgot to check the nh3 LARMF compensation. In order to not get the check engine light and the code 520372 16 i have to removed the def dozer and also remove the crystalized def at hole, then put back the def doser. I have to unplug the hole with crystalized def 3 times a day. By doing this the code 520372 16 won't come on. First mechanic told me i need a new one box and second mechanic said it needs a new def pump. But a i have some doubts on both opinions because the scr efficiency test pass and there are no others codes for bad def pump and one box. The code 520372 16 relates to the hole of the def doser getting clogged? Or is another problem? What could it be?I would appreciate if can give me an advise of yours if i need the one box or def pump.
Hi. This code happened to my 2018 Cascadia. I replaced the outlet nox sensor. I run an SCR efficiency test and problem solved. NH3 should reach 1.0
Check the DEF pump by running a ADS self check then do a DEF quantity check to make sure your within range.
During the regeneration your NOx outlet should be around 50 ppm.
Had this problem with 17 cascadia dd15, first test lasted 3k miles, did it again this time it was only 1k miles. 3rd time it did not pass. New def pump and both Nox sensors helped us resolve the issue. Hope it helps.
We are wasting time, fuel, and resources just to "protect" the environment... nothing is even being accomplished 😂😂😂
These systems definitely consume a lot of resources.
This is most idiotic thing that someone(engineer) could come up when decide to implement on ACM programing !!! 3-4 hrs of regen to get read of codes....some people deserve prison time! I am switching to KW they seem like much less hassling regarding DPF programing strategic. From my experience KW will not derate that often like DD Engines due to better ACM MCM programing strategic. Would like to hear if I am wrong.
PEDRO thanks for posting this video !
I agree, in order to clear the code or codes you have to burn fuel for 3-6 hours.
But , we are saving the environment ! what a joke good video !
@@Diezeling I agree, this definitely needs to be improved. It doesn’t make sense to run an engine for 4-6 hours just clean a filter.
Am from Europe and we don't use this cascadia
To learn the full steps to diagnose this systems what manual do you advice
Thank you
There are books that Detroit sells to assist with troubleshooting the after treatment. However, some of these I have learned from other techniques and technicians that share inside information they have leaned from the dealership when they worked there. Also, just working on these you will start to try different things
Hey Pedro I have a question about the value why it doesn’t match with the max to the right end column is there still something wrong if it doesn’t match
Max is what is observed, when the value drops. That could be something with the DEF dosing, DEF pump or possibly a sensor issue.
Would have to see what other codes are present and run a parked regen in order to see what the numbers are.
Are you getting other fault codes ?
Those where my values when my codes pop up
Description
ASL: NH3 LARMF compensa..
Device
ACM21T
Value
0.82123
Unit
Min(Observe... Max(Observ..
Max
0.50000035.. 1.99218893.
ASL: NH3 LARMF compensa...
ACM21T
Value
0.92236
Min(Observe... Max(Observ...
Min
0.77954
0.92236
0.50000035.
Max
1.99218893..
And these where after the scr test and my codes disappear
° DEF inducement DEF lamp active
D DEF inducement CEL lamp active
521049
521052
[UDS-611 ACM21T - Aftertreatment Control Module 2.1
田
• SCR closed loop control at maximum limit
520372
J1939-61 - Exhaust Emission Controller
Aftertreatment 1 SCR Conversion Efficiency - Condition Exists
4364
These are the codes I received
The problem I’m having is I have the same “permanent loop” code but it’s actually making my light stay on. Will it go off eventually or put me in limp mode?
I have seen it put trucks into derate.
Do you have the software?
You will need to check a few things.
1- DEF pump speed
2- DEF quantity test
If all is good, proceed with a parked regen and if that is successful. Pressures, NOx efficiency and temperatures.
3- go directly into a efficiency test immediately after the parked regen. The LARMF has to be at .092 or higher in order to clear the code. The test will stop on its own and can take 4-6 hours from start to finish.
@@CarlosDieselElectricwe do have software but software we have doesn’t show the SCR LARMF levels. we have done all those steps.
All we done was changed the NOX sensor and now this code is going off causing the MIL light to stay on
@@collin4380 during the parked regen. What is the DOC pressure?
What is the NOx efficiency ?
Also, what year is the truck? How many miles?
@@CarlosDieselElectricupdate; after completing 3 scr test we cleared the code and it stayed away. Drive a hour down the road and it’s still gone.
I’m sure it will be back but if it comes back I’m deleting it.
@collin4380 glad you took care of it. Sad that it takes that many attempts to clear. Detroit needs to do better.
I have a 2019 with a 4360 FMI 31, SCR inlet temp not warm enough, i already checked for exhaust leaks and also replaced the temp sensor with no luck, any ideas?
What other fault codes are you getting?
@@CarlosDieselElectric thats the only one, it has a DT12 transmission and i installed a PTO on it and it only comes on when im running it so im thinking it might have something to do with it
@magnovska3979 possible, depending on how it was connected, that may effect things. Hard to say
@@magnovska3979 Also, you may have a ACM issue or harness issue. Try swapping the ACM with a similar truck and see is that works. If you need to purchase the ACM, they are fairly inexpensive but try using a test computer first.
@@CarlosDieselElectric ill try that, also the PTO was never programmed to it, I installed it my self so when I engage it and rev it throws that code, i think i need to get it programmed so the system knows what's going on
What if mine never goes up and stays the same?
A few things to check or look at.
Amount DEF being dosed?
DEF pump RPM
NOx efficicency during the regen.
What are those numbers?
What software do you use exactly ?
diagnosticlink.nexiq.com/DTNA/Default.aspx
This is the exact software I use. It is a subscription based but well worth it. I use the Standard version which allows me to make many changes except for programming (updates).
@@CarlosDieselElectric thank you 🙏🏼 love your channel. Want to stop by for a service in July
What should I do if it failed?
What are the numbers? Tell me more. Did the regen pass? Then what happened after
@@CarlosDieselElectric the larmf went from 749 to by the end was 719
Nox in was avg 175 out was 245
Did regen first then jumped right into the scr test
@@CrazyxxxUkraine during the regen, what was the NOx efficiency?
What were the numbers?
@@CarlosDieselElectric near the end was 125/350
epa is a slush fund.
Having a dealer trying to charge me 19k please need advise on this work order contact me asap need help!
Need more information, are they saying the One Box is bad?
So basically, regular drivers can't do anything unless you buy the software diagnostic link. How exactly did this help anybody on the road and having issues.
For drivers that have the software it helps. But for most it does not. I have a few customers that have the software.
@CarlosDieselElectric So, the correct title of the video should be if you have DD15 software and have this issue. Do this to fix
shutup and watch... nexiq usb3 is $800, DDDL 8.18 is $100 on mhhauto
@@fozman845
only diagnostic will cost you $350... everything on the video is around $1500@@fozman845
Dude stop crying and buy the software. The guy is at least helping with the info.@fozman845
This video was a big nothing burger, other tan a typical regen and an scr regen. What they didn't include was them cleaning the dozer or at least they should have.
Did that, just didn’t show it. Appreciate the feedback back