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HELP with removing DEF/ urethra injector for replacement

20K views 19 replies 13 participants last post by  speters53 
#1 ·
I have a 12 LML that is showing Exhaust fluid quality poor message and at this point I'm limited to 55 MPH so driving a borrowed vehicle.
I took it to a shop since I haven't been able to clear that message I've done the RFQT test a few times and always fails I ran through the full battery of tests where I do a service regen then the RFQT but it still fails. The downstream Nox sensor is normally about 70% less (120 UP and 30 down) but its still failing.

Mechanic thinks issue is with the Def injector the stream might not be clean / good shop was closing so I just ordered one from Rock auto waiting for it to arrive today but the Magical question is how do you remove the injector so I can try and actuate the injector outside the vehicle to see if it is truly bad or not. The below picture shows how I removed the locking plate. I've tried to twist and pull but the injector isn't coming out am I missing a release spring or something?

There were some ECM updates that were also done but still no change.

I just want to remove the injector and test it to see if it is actually spraying. I can disconnect the line and actuate the pump and it will pump out the fluid no issues.

I'm open to ideas on how to remove this or what else i can try / do. I do have a hand held scanner that can do everything the Tech 2 is able to do.
 

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#3 ·
From Amazon its the Launch X431 PROS Mini Bi-Directional Diagnostic Scan Tool Full System Automotive

I can NOT update firmware but can run tests and see sensors and all that fun jazz
 
#5 ·
I am wondering about the "urethra injector". I might be wrong but all us little boys have an injector😜
 
#10 ·
#7 ·
I figured you or Hook would respond first!
 
#11 ·
Good News finally got the Injector out After 1/2 can of PB blaster and sitting there and shaking and pulling on it for 10 minutes finally came out. The rubber gasket was hard as a rock. The tip of the injector was all white with DEF residue so I swapped out the injector.


UGGG Still having issues the RFQT still won't pass keeps failing. I've drained a bunch of the fluid already, ran / tried running regen but not wanting to complete but not giving reason why not completing during test EGT's not raising over 450 but if I drive it temps hit 1000. I trued cycling all of the heaters for 2 minutes then cycling the key for 2 minutes, running the RFQT still fails. At a loss and don't have extra money to just throw at maybe parts. During RFQT the test the down nox sensor is right at the threshold (70%) where its supposed to be but still won't pass.

I have 50 miles till I'm stuck at 7 MPH HELP anyone? Note I'm not driving it right now trying to get the test to pass before I drive it borrowing car that I need to return soon.
 
#15 · (Edited)
FWIW, the def residue can often be cleaned off the old injector with water. (At least as a trial before replacing).


Old threads will show that the most common cause of 'poor def quality' was that one or both of the NOx sensors were in need of replacement.

The LML doesn't measure def 'quality' directly. It measures the NOx level before and after def injection and looks to see that the expected change in NOx level occurs. When it doesn't it assumes the problem is the DEF.
Unfortunately, when the NOx sensor(s) drift out of calibration, the computer has no way to know this.

Solution was to replace the sensors and run the service regen procedure to teach the new sensors to the system.


Lots of old threads on here about 'poor def'.

Typical was the dealer blaming he customer for bad def.
Dealer not taking a sample of def and doing a test. DEF that does get tested comes back ok.
Drop tank, change def. Send customer on their way.

Nox sensor is on the edge of working correctly, so the truck may be fine for a little while. Of course, the problem returns. Usually while still running the tank of 'better' def that the dealer supplied.

Eventually it became known that NOx sensors were the issue.
The newer NOx sensors were better, so typically the issue did not return after replacement.

Early LML's were the ones that most commonly had the problem.


I don't recall ever reading of a way to 'field test' the calibration of a NOx sensor.
My bet is that replacing the off cal sensor (or both) will correct your problem -- permanently.
 
#12 ·
Look at attached video, think it might help.
I was involved in meetings when DEF was being discussed and there was always a lot of concern about people not using the correct fluid and as such fluid sensors are installed. These are very sensitive to Urea concentrations and it does not take much in the way of contamination or misfueling for it to be an issue. DEF is horrible stuff, it easily comes out of solution and crystallizes and will not go back into solution at all not matter what you do. So it sounds like you have an issue either related to the fluid or the sensor.

 
#16 ·
So today I pretty much emptied the Def tank filled it back up with 5 gallons of new fresh DEF (Blue dex) I did reset the (think called) redundant fluid level
I ran a service regen to get everything nice and hot soot level is 0
I ran a RFQT and while testing the Nox Sensor 1 is at 132 PPM and Nox sensor 2 is at 22 PPM when it failed
Drove around block to grab some more Diesel
Disconnected tech 2 waiting 2 min
Ignition on cycled all heaters (def heaters 1-3 for 1 minute same key cycle rand the RFQT and this time Nox 1 168 ppm and nox 2 23
I ran another regen since soot was up to 5 grms (yes I know probably over kill)
I ran another RFQT and failed again Nox 1 86 ppm Nox 2 15 ppm

I don't know what else to try I'm down to approx 9 miles before I'm stuck at 4 mile per hour. I don't want to just guess and start throwing sensors and parts at it esp since the NOX sensor seems to be within the correct range.
 
#18 ·
I chanced it drove it 0-55 4-5 times came home ran a full regen then the RFQT and it passed been driving it ever since. Sorry didn't mean to leave everyone hanging.

Ironically today driving to work my CEL came on for the P20ee haven't had a chance to look at that yet... uggg
 
#19 ·
I have a 12 LML that is showing Exhaust fluid quality poor message and at this point I'm limited to 55 MPH so driving a borrowed vehicle.
I took it to a shop since I haven't been able to clear that message I've done the RFQT test a few times and always fails I ran through the full battery of tests where I do a service regen then the RFQT but it still fails. The downstream Nox sensor is normally about 70% less (120 UP and 30 down) but its still failing.

Mechanic thinks issue is with the Def injector the stream might not be clean / good shop was closing so I just ordered one from Rock auto waiting for it to arrive today but the Magical question is how do you remove the injector so I can try and actuate the injector outside the vehicle to see if it is truly bad or not. The below picture shows how I removed the locking plate. I've tried to twist and pull but the injector isn't coming out am I missing a release spring or something?

There were some ECM updates that were also done but still no change.

I just want to remove the injector and test it to see if it is actually spraying. I can disconnect the line and actuate the pump and it will pump out the fluid no issues.

I'm open to ideas on how to remove this or what else i can try / do. I do have a hand held scanner that can do everything the Tech 2 is able to do.
How did you “actuate the pump”? When I disconnect the line with the truck running no fluid is pumping.
 
#20 ·
I just replaced the DEF injector as part of other things to clear message about poor def. It is a pain to unscrew the 2 nuts, sure could have cleaned the injector for it was covered in black def fluid, but why go through putting it back on only to have to take it off again and put a new one on. Also replaced NOX #2, drained the def tank and refilled with new fluid. Ran a Reductant Fluid Quality Test, it failed the first time, went through the procedures found in a bulletin and PIP and got it to pass on the second go around. Below are the bulletin and PIP links.
Hope this helps.
 
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