DEF question

[HemiHavoc]

I just bought the truck (2015 67k miles) and yesterday the dreaded "service def system see dealer" message came up. No mileage until limp yet thankfully. I pulled the line off the injector and pulled the injector to see if there was any crystallization. Surprisingly there was none, so now I want to make sure the pump is working. Does the pump run all the time that the truck runs, or just in regen? If it doesn't run all the time, how can I make it run to make sure I'm getting fluid to and out of the injector?

 

[18CrewDually]

#1 rule in any modern day vehicle (1996+).
CHECK for Codes.
It could be a def heater or anything else in the system. Poking & hoping gets expensive.

 

[GTyankee]

DEF does not enter the fuel injection system
It is sprayed directly into the exhaust system

watch video

Ram Jeep Ecodiesel Important Exhaust Fluid Tips and Repairs

3.0 Ecodiesel owners must watch! Common issues with Diesel exhaust fluid systems, how to prevent them and replacing a key DEF components!

www.youtube.com

 

[HemiHavoc]

I just want to test the def pump and rule that out as a culprit

 

[HemiHavoc]

#1 rule in any modern day vehicle (1996+).
CHECK for Codes.
It could be a def heater or anything else in the system. Poking & hoping gets expensive.

Code is a P2298, but it says service def system and I just want to make sure it's moving def fluid. It hasn't moved fluid on the gauge in the 800 miles I've driven

 

[HemiHavoc]

DEF does not enter the fuel injection system
It is sprayed directly into the exhaust system

watch video

Ram Jeep Ecodiesel Important Exhaust Fluid Tips and Repairs

3.0 Ecodiesel owners must watch! Common issues with Diesel exhaust fluid systems, how to prevent them and replacing a key DEF components!

www.youtube.com

Understood, but there is still a def injector in the exhaust and that is where I'm checking and what I'm messing with

 

[GTyankee]

In that video, it shows what heat will do to the plastic parts

 

[18CrewDually]

Code is a P2298, but it says service def system and I just want to make sure it's moving def fluid. It hasn't moved fluid on the gauge in the 800 miles I've driven

That code is for #2 Nox sensor. It's in the exhaust pipe after the treatment system, right where the tailpipe bends to go up over the axle. Has nothing to do with actual def dosing. It monitors the efficiency of the system. Check the plug and wiring first but they do go bad. Also make sure theres no exhaust leaks.

6.7 Cummins nox sensor #1 and #2

6.7 Cummins nox sensor #1 and #2Intake nox sensor fault code for a bad sensor is. ( P20EE scr nox catalyst efficiency below threshold bank 1)This work has be...

youtu.be

 

[HemiHavoc]

That code is for #2 Nox sensor. It's in the exhaust pipe after the treatment system, right where the tailpipe bends to go up over the axle. Has nothing to do with actual def dosing. It monitors the efficiency of the system. Check the plug and wiring first but they do go bad. Also make sure theres no exhaust leaks.

6.7 Cummins nox sensor #1 and #2

6.7 Cummins nox sensor #1 and #2Intake nox sensor fault code for a bad sensor is. ( P20EE scr nox catalyst efficiency below threshold bank 1)This work has be...

youtu.be

So if the def isn't pumping/cleaning the filter then that couldn't be a cause for the #2 sensor to sense issue? My head says no def pumping (bad pump or injector) = bad O2 reading = P2298 code. I would like to verify that the pump and injector are functioning properly because I have yet to see a change on the gauge and this code

 

[18CrewDually]

If you had a code P2048 then I'd look at the def injector, but you didn't list that code.

 

[HemiHavoc]

If you had a code P2048 then I'd look at the def injector, but you didn't list that code.

So let me rephrase the question again, could a bad def injector cause issues in the filter that would cause the 2nd O2 sensor to read incorrectly? Also does anyone know, truck running, line disconnected from injector, should the truck be pumping def fluid?

 

[18CrewDually]

If the tank was full, the gauge won't neccesarily move off full for 500-1000 miles depending on load. The sensor is not your conventional fuel tank style sensor and it does not go to the top of the tank.
Also if the pump was not working or injector circuit bad it would show a code.
What are you using for a scanner? Do you have AlphaOBD?

 

[jejb]

So let me rephrase the question again, could a bad def injector cause issues in the filter that would cause the 2nd O2 sensor to read incorrectly? Also does anyone know, truck running, line disconnected from injector, should the truck be pumping def fluid?

With no load, it won't be working much, if at all. I just made a 900 mile trip towing my bass boat. Mostly interstate. Used about a gallon of DEF. Probably wouldn't have used half of that with no load.

 

[David Oakes]

So if the def isn't pumping/cleaning the filter then that couldn't be a cause for the #2 sensor to sense issue? My head says no def pumping (bad pump or injector) = bad O2 reading = P2298 code. I would like to verify that the pump and injector are functioning properly because I have yet to see a change on the gauge and this code

First, it isn't an O2 sensor, it is a NOx (nitrous oxide) sensor.

A very simple explanation is that sensor one takes an exhaust gas reading before the def is injected into the exhaust gases and then sensor 2 reads the gases afterwards. There has to be a specific range of change in the amount of NOx in the exhaust or it will throw that code. It has been my experience with Cummins engines, both big truck Kenworth/Cummins PX7 and PX9 engines, as well as a 2016 eco diesel and my current 2022 3500 that the most likely cause of that code (the plain text of it) is NOX sensor #2 failure. Once that sensor has been changed, other items can also cause the problem, but Cummins fault finding says change that first so you aren't chasing your tail with guessing.

 

[RedRam55]

Seems like you are dead set about fixing the injector...so go for it. Then you can fix the NOX sensor when you are done....

 

[Steve Hammer]

At 52k my 2016 3500 got the DEF service notice. Long story short injector was clean. Took into dealership, pump had gone out. Dealer installed a new pump (good luck getting one) put back together and confirmed all was working. So what caused the pump to go out, the injector had failed causing the pump to over work and go out. Dealership discovered failed injector after installing new pump. What is really disgusting/cheap/not accountable by RAM, DEF is required for emissions however RAM does not count or cover as past of emissions. Talk about a scam. I now have a second injector as a spare. I am thinking this injector should be replaced every 50k. My other practice is I only fill DEF tank 1/2 full, run it down and 1/2 fill again. There is no question not driving your truck every day or letting it sit for long periods DEF is not your friend.

 

[Siff]

At 52k my 2016 3500 got the DEF service notice. Long story short injector was clean. Took into dealership, pump had gone out. Dealer installed a new pump (good luck getting one) put back together and confirmed all was working. So what caused the pump to go out, the injector had failed causing the pump to over work and go out. Dealership discovered failed injector after installing new pump. What is really disgusting/cheap/not accountable by RAM, DEF is required for emissions however RAM does not count or cover as past of emissions. Talk about a scam. I now have a second injector as a spare. I am thinking this injector should be replaced every 50k. My other practice is I only fill DEF tank 1/2 full, run it down and 1/2 fill again. There is no question not driving your truck every day or letting it sit for long periods DEF is not your friend.

You can also just delete the DEF if it keeps giving you problems; the environment will take a hit, but the truck will run fine.

That's what I did when I had a secondary air gate get stuck on my 07 WRX just after the 3-year factory warranty expired, with the only purpose of that gate being to reduce emissions until engine reached operating temp. Once Subaru refused to repair as part of the emissions warranty, I just sealed the gate shut to prevent leaks and disabled the sensor and code and it ran fine without it until I traded it 10 years later.

 

[18CrewDually]

You can also just delete the DEF if it keeps giving you problems; the environment will take a hit, but the truck will run fine.

That's what I did when I had a secondary air gate get stuck on my 07 WRX just after the 3-year factory warranty expired, with the only purpose of that gate being to reduce emissions until engine reached operating temp. Once Subaru refused to repair as part of the emissions warranty, I just sealed the gate shut to prevent leaks and disabled the sensor and code and it ran fine without it until I traded it 10 years later.

Yeah it doesn't work like that Muchacho. You can't just block it off or delete it. You'll end up derating the truck to 5 mph.
Stick to Subarus.

 

[Siff]

Yeah it doesn't work like that Muchacho. You can't just block it off or delete it. You'll end up derating the truck to 5 mph.
Stick to Subarus.

I see, my mistake

6.7 Cummins DPF Delete Guide​

6.7 Powerstroke DPF Delete Guide​

3.0 EcoDiesel DPF Delete Guide​

 

[HemiHavoc]

Seems like you are dead set about fixing the injector...so go for it. Then you can fix the NOX sensor when you are done....

Not dead set, just wanting to make sure the system is functioning properly by trying to witness it pump def. I used to have an 05 duramax, so this DEF stuff is foreign to me. The service def system message lead me to believe the def wasn't pumping and that would cause nox2 to read incorrectly and throw the code. I now know that to not be the case, so I am looking into the sensor now. Thanks for the help guys!