Check out this post. Especially towards the end where he actually fixed it.

Exhaust Fluid Quality Poor, YAY

Had this pop up on me on the way home from work yesterday. Able to get home and its showing 20 miles before my first reduction. 2014 with 142k miles. It has had the Nox and DEF tank recall done last year. I took this car over from my wife about a month ago when I bought her a 4 Runner. Her...

www.cruzetalk.com

 

I had read that thread before, but I had forgotten about his experience with NOX2 not reading until at least 10 miles of driving on a car that had already been warmed up. Still not 100% sure this was the problem I had with the new sensor that failed for me. I did the EFQT which runs the engine at 3K rpms for 30 min with the new sensor and got nothing. I don't remember EGT's from the time, but certainly all 3 were plenty hot, so it seems unlikely that the SCR system didn't get to operating temp.
I'm still waiting on the other new sensor I ordered. I have already sent the other one back and got a refund, (couldn't wait because I only had a week to return it.)
Like I said, I have read a few people comment that a new NOX2 sensor read zero and they couldn't get it to read. I honestly wish I had just decided to take the car for a decent drive now to see what would have happened. Right now I still have a CEL u209e for NOX2 sensor not detected which only came up after I put the new sensor in. Old sensor is still just stuck at 99, new sensor was stuck at 0.

 

OK...... I got the second new NOx2 sensor. I installed it. If anything it was even more of a problem. I warmed up the car and then drove about 20 miles. NOx2 read 0 the entire time, NOx1 took far longer ~10 minutes before reading. I got and tried running the service bay test, and it wouldn't run, gave me an error message and "limit out of range". A new DTC popped up in addition to the U029e for lost communication with NOx2, now has code for U02A3 for lost communication with particulate matter sensor. I thought maybe DEF was below temp so I put a heater under the tank for about 45 minutes, still wouldn't run the test. I swapped the old sensor back in, NOx2 immediately read 99 and stayed there, but now the service bay test was able to run. The DTC for NOx 2 status still showed but went from "current" status to "history", the code for the particulate sensor showed history both times. Codes will not clear though. Any ideas???? I ready to sell/ trade in the car. I've been without it for almost a month. It's really sad because the car runs perfectly and drives great. I drove it to the Rose Bowl ~1600 miles round trip just prior to all this BS. and car was awesome. Very frustrated right now.

 

Oh also with the new sensor in the warning message changed again from "Exhaust fluid quality poor" to "Service Exhaust fluid system". With the old sensor back in it stays reading fluid quality poor.

 

Complete guess here but are you able to put the new sensor onto the old sensors electronics by unplugging the old sensor and plugging in the new sensor? If not it would be cut and splice.

I am speculating the electronics work but the actual sensor doesn't.

How to fix and replace a faulty Nitrogen Oxide NOx sensor control unit

All of the sudden "Check Engine Light" appeared in dashboard and it's pointing to faulty nox sensor error code? Visit this guidline to fix this by yourself!

xenons4u.co.uk

 

Also have you tried to clean the original nox sensor?

 

Well its gone, sold it earlier today. Hopefully the guy that bought it has better luck. He definitely knows diesels better than me. He also has the option to delete if he can't fix it because he can register in a county that doesn't do emission testing. Thanks for all the help.

 

Looks like there is hope....

 

Okay for a 3rd highjack on this thread? It sounds like I'm late to the party, from what I gather I might be close to bumpinalta (~1600mi round trip to rose bowl from northern utah) and we could have shared parts.

So anyways I got the DEF quality poor light on, I drive 45mi one way all highway 65mph+ to work every day. 2014 cruze, original owner, 154k miles. I had the NOX recall done early on, like sub 50k miles I think. Only recent repair is p227b which I had the dealer fix with a new ECU, that was about 1000 miles ago. I did the DEF heater around 20k miles ago.

Pulling the codes on gretio I get: P249D and P204B. We all know what P249D is but P204B appears to be: "Reductant pressure sensor performance general failure". Both of these code are in "history" though so I don't know how long ago they were present.

First thing I did was pull the DEF injector, the nozzle looks clean and was visibly wet. My assumption is that the wetness on the nozzle tip and inside the pipe is indicative that DEF is being injected. I cleaned the external surfaces and reinstalled.

Pulled up Gretio and ran a service regen, then a DEF quality test. Failed. NOX1~58ppm and NOX2~20ppm

Replaced NOX2. I was lucky enough to find a OEM one on rockauto go in stock briefly, I sort of feel bad for the other guys waiting and looking for one. Anyways I installed it, drove it around 10 miles, service regen, DEF quality test. Failed. NOX1~65ppm NOX2~16ppm

So now I'm thinking maybe my pump or injector is not functioning right. I pulled the injector and performed a DEF quantity check. It spit out about 50ml of fluid which is a pass according to the bulletin I referenced. So that would rule out my pump and injector.

Drained and filled with a new bottle of BlueDEF (date code 2/21 - a little old but I read 1 year is still okay)

Ran a DEF fluid quality again to attempt to purge the DEF lines- NOX1~68ppm NOX2~14ppm. Then I ran a service regen, and a final DEF fluid quality: NOX1~70ppm NOX~12ppm.

I feel like every time I fluid quality test it gets slightly better, but I'm worried about stressing the DPF with too many service regens. At this point I'm not sure what to do. Wondering if maybe NOX1 is under reporting, or my SCR is just getting tired. Any one have any thoughts?

 

It might not be passing because of the "history" codes.

It might just need a drive cycle completion to go back to normal IF it doesn't throw any new or previous codes during the drive cycle.

 

That did it!!! After work today I pulled and inspected the NOX1 sensor, didnt look too sooted up but I cleaned it with MAF cleaner and reinstalled. Then I ran a DEF quality test, failed NOX1~70ppm NOX2~19ppm. That's about the time I saw your message and wondered, maybe I should clear the codes and try again. I tried to clear them on Gretio but could not get it to go through, KOEO nor KOER. I pulled up a different scanner app and cleared that way then went back to gretio to do another DEF quality test. PASSED! NOX1~70ppm NOX2~18ppm. No more death clock countdown!

To clarify, my CEL was not on. It went on right after it started the death clock countdown but the CEL cleared about halfway home that day and has remained off since then. Now hopefully it stays cleared. I'm not sure what ended up actually being the problem, all I physically did was: NOX2 sensor replacement, DEF drain and fill, DEF injector cleaned, NOX1 sensor cleaned. I performed at least 4 service regens and probably around 7 or 8 DEF quality tests in between all those actions. Advice for anyone else, clear the codes before trying to clear the countdown with a DEF quality test!

 

Sweet. Nice to hear a success story for a change.

 

@Snipesy - Do these cars do DEF quality testing on their own periodically? I can't imagine the intention from GM is that you must have it done at a dealer. Shouldn't the cars 'self heal' after a false positive code? Is draining the DEF and refilling and driving it until death clock countdown goes away enough?

 

During normal highway driving yes.

The advantage of the quality test is it’s stationary. And after 4mph it’s basicially your only option.

 

Hello guys, 2 years after I resolved my issue (the other post someone one linked) Im back to having the same issue. This time I have a P20EE code, I replaced the tank heater again with no luck, then replaced the upstream Nox1 sensor, (toe P20EE code) it cleared the fault for 30 mins or so but came back. The tablet I use with my USB cable took a dump so Im debating on getting another tablet an see if the USB cable will work with the Gretio app or buy the MX+ OBD tool and use it bluetooth with my phone. The guide that Snipesy put together looks like really good info. Once I get either a new tablet or the MX+ tool I'll start working on my car again an hope I can get everything cleared up!

On a side note, its funny I already have the exact BAFX scanner that he said will not work. I use it in my truck pulling my camper to watch oil and trans temps with TorquePro

 

I wanted to post an update. I ordered the MX+ OBD tool that Snipesy posted in the Youtube video. After swapping the DEF tank heater again and the NOX1 sensor, I ran the DEF Fluid Quality Test per the guide FOUND HERE. My car passed the test, after the test finished and my car showed passed the DEF Fluid quility poor fault cleared. My car is out of limp mode and back on the road. I understand why all the emission junk are on newer vehicles but I still wish I could rip it all out and tune it out of my car so I never deal with it again!