Peterbilt with a Cummins, emissions derate due to a bad sensor. What to look for and how to fix.

2021 Peterbilt with a Cummins engine, emission derate was coming up on the display. Once we connected to the truck using our Insite software we were able to see the fault codes and make the necessary repairs.
The DEF level sensor is a combo unit that measures the DEF level, DEF temperature and DEF quality.

[@Galarid87]

I got an emissions code once for low nox conversion. I did my research with cummins Quick Serve. Emission codes are the worse, it had me checking nox sensors, Def quality, Def sending unit, Def doser unit. I ran down the checklist even dropped the Def tank checked the Def quality for proper Uria/water mix because there are rumors of truck stops watering down there def, checked the sending unit, and the heater element for possible coolant contamination, I know the struggle with those tanks. At the end of it all, it was a faulty scr filter! Emission codes can become a real problem. But you learn a lot.. thanks for sharing 👍

[@adrianluna6431]

Thanks for the video I'm having the same issues on my 2020 kenworth t680, u save me alot if money sir ill stop in Albuquerque NM and replace it my self

[@RESTLESSW900L]

Great video

[@chrismayancela8792]

Yea thank for showing
How to remove it and replacing it

[@pedropedro2837]

Thanks

[@turksir74]

I had the same issue on my 2018 579. Mine was the def quality and level sensor. Had to replace it.

[@mudpuddle8805]

DEF quality sensor does quality, level and temperature. They go bad often. The sensor costs about $450. There is an electrical connection as well as coolant connection. The coolant elbow is easily broken.sensor failure will derate power and drop you down to 5 mph limit after a certain number of miles.

[@oscarsegovia6083]

Have you ever install a bad sensor from the dealer i just replace one cause i wasnt getting any def level so when i install the new one and added def the def level goes up and down up and down so the check engine light doesnt go off and the truck stays in derate mode do you think the new sensor is bad or it could be something else

[@Unduplicatable]

Wow that’s just *SO* environmentally friendly -_-

[@chuy25]

How much is that set up and membership

[@HectorWPadilla]

Great vid!! What’s your verdict on the Paccar engine overall?
Also, you edit your videos on your day off 😅

[@CarlosDieselElectric]

My day off is the only opportunity I have.

[@CarlosDieselElectric]

The Paccar engine like the MX13 is ok and could be better but does require a different set of tools and knowledge to work on. That is that hard part, there isn’t too much out there as far as information goes and you have to have the software. To make changes or parameter changes it requires the tech to contact Paccar. They make the changes then the tech can make the updates. It is ridiculous to have that many steps involved. Detroit, Cummins are the way to go. Because you have more people that can work on them.

[@kellykolnes1954]

What a pain in the ass job on a Minnesota truck.

[@CarlosDieselElectric]

Definitely a bad design from #paccar. They should have designed that with the tank more accessible, especially the DEF sensor

[@stevend8656]

Great video.. what would that job cost us retail?

[@CarlosDieselElectric]

The part is around $300-400 depending on the model number. Labor is about 4 hours from start to finish. The job isn’t that difficult but might require the software to complete the repair.

[@RADIORAHEEM402]

So in a dd15 poor quality code mean the def header is bad? Or the nozzle in the onebox

[@CarlosDieselElectric]

Not necessarily. Poor quality DEF fault code is kind of a default code.
For example, if you have low efficiency fault codes (NOx). The system will tell you poor DEF quality because you need to check the DEF quality, check the Doser for any obstructions or blockage because these are things that can cause low NOx efficiency.
What kind of code or codes are getting?

[@RADIORAHEEM402]

@CarlosDieselElectric typical 4364 occasional def quality. But recently it started giving me VERY LOW nox. And the other week ago in the rain, the engine shut off on me while driving code; in and out nox and doc temp faults. Once I stopped and restarted the engine it went away and no more problems after the rain my assumption would be frayed wiring somewhere but before this, 4364 when climbing and def quality

[@oguensjulien6935]

I just got my 2022 KW900 from the Jacksonville FL dealer for the same problem. Guess what , truck has only 116232 miles on it. Warranty don't cover it . Truck spent two weeks there they said that sensor will take 5 days to be there

[@CarlosDieselElectric]

That is terrible to have to wait. Especially with the supply issues that are not your fault

[@Nihil2005]

I call them Stealerships

[@willenglish-robinson5292]

This would have been more helpful had you shown how to remove the def tank and the bad sensor

[@mark929rr5]

You will probably replace this sensor about every 12 months for the life of the truck... absolute garbage

[@CarlosDieselElectric]

I agree, terrible design.

[@georgenguyen6047]

Thanks