Exhaust fluid quality poor, please help. :(

T

Tyger255

New member
Hello, brand new to the forums and in a bad spot for some help. Took over this 2014 diesel cruze from my wife about a month ago. 146k miles. My commute I'd 150 Mike's round trip. Leaving work to go home last week I get the exhaust fluid quality poor message and 100 miles till 65mph max. I stop on the way home and add new DEF thinking the fluid was low and no change. The car had a P20E4 fault and I changed the EGT 2 & 3 sensor, cleared the codes and they haven't came back. The car runs great, not sure what to. I had the DEF tank and Nox sensor recall done a while back. Someone on another site suggested checking the DEF injector. I've searched and cant find any info on this injector. I did find a labeled photo that gives me a rough idea where it is. I'm planning to pull and try to clean the Nox sensors to see if that helps. I was going to replace them but they are $200 each, I cant find any good info on how to test them, (if there is a way to test). I hate to take it to the dealer because the only info i can find on this problem are people spending 3k st the dealer to fix the issue with no real explanation on what the problem was.

I'm lost on where to go from here. I would expect it to have some code along with this problem to help point me in a direction but none. I'd appreciate any help.
 
Is the a DEF pump? I have no experience with these little ones, but I'd assume something has to create pressure. On the ISX and Midrange stuff, there is a filter in the doser pump.
 
Its probably the reservoir module in the tank again.

Hell, I get the P20E4 code all the time, too.
 
RascalMafia said:
Had the same thing happen. Probably the DEF heater

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So you had he same message and replace the tank heater to resolve your issue? Would the tank heater going out cause this issue even though the temps here in Ga have not been below freezing? Google list the freezing point of DEF as 12F, I think the lowes it's been here was low 40F. Could be if it does not see the working heater it cause this fault. Would be nice if it atleast gave that info. If there is a temp sensor as part of this unit I wonder if putting a heater in the trunk to bring the temp up would change anything with this message.

Cant find much info for the heater, but I see the kit for about $150 or so online, called the dealer and it had a 12 month warranty from being replaced under a recall. That was about 14 months ago. If the rain will move off this morning I'll pull it apart and take a look.
 
Does that car have a def quality sensor somewhere or does it just use the NOx sensor? I've seen setups both ways.
 
Tyger255 said:
So you had he same message and replace the tank heater to resolve your issue? Would the tank heater going out cause this issue even though the temps here in Ga have not been below freezing? Google list the freezing point of DEF as 12F, I think the lowes it's been here was low 40F. Could be if it does not see the working heater it cause this fault. Would be nice if it atleast gave that info. If there is a temp sensor as part of this unit I wonder if putting a heater in the trunk to bring the temp up would change anything with this message.



Cant find much info for the heater, but I see the kit for about $150 or so online, called the dealer and it had a 12 month warranty from being replaced under a recall. That was about 14 months ago. If the rain will move off this morning I'll pull it apart and take a look.
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Yes, mine failed in GA in July. I had a ton of emissions issues with mine so at the time, the dealer replaced all sensors (again), heater, pump, tank, pretty much everything except the DPF and SCR which had already been replaced twice.

But the claimed the heater was what caused the issue.

There is a DEF quality sensor as well.

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mhuggler said:
Does that car have a def quality sensor somewhere or does it just use the NOx sensor? I've seen setups both ways.
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I have no idea, my very limited understanding is it checks between the Nox 1 and Nox 2 sensor. If those readings are not correct it can cause this issue but that's also gives a CEL and Nox sensor fault code. I have no codes,

I think I'm going to order the DEF heater kit and see what that does.
 
Tyger255 said:
I have no idea, my very limited understanding is it checks between the Nox 1 and Nox 2 sensor. If those readings are not correct it can cause this issue but that's also gives a CEL and Nox sensor fault code. I have no codes,



I think I'm going to order the DEF heater kit and see what that does.
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That's your NOx conversion equation to ensure the system is dosing correctly and everything is acting as designed. I'm pretty sure there is also a DEF quality sensor in the tank as well.

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Does EGT 3 (the reason for the 20E4 code) have something to do with the amount of DEF delivered and when? I read that somewhere, its probably wrong....
 
TheBac said:
Does EGT 3 (the reason for the 20E4 code) have something to do with the amount of DEF delivered and when? I read that somewhere, its probably wrong....
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Not sure about that, I'm sure there is some type of temperature correlation but don't know enough about GM emissions strategy. My system stopped working about 2 years ago...

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Ordered the tank heater assembly today, $160 after S&H. 7 to 10 days for delivery. Thank you all for the input. I will report back after I get it swapped and put some miles on it. I found and article today when doing research on this part that says it can take up too 100 miles of driving to clear this message.
 
TheBac said:
Does EGT 3 (the reason for the 20E4 code) have something to do with the amount of DEF delivered and when? I read that somewhere, its probably wrong....
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I don't know which egt position the ecm is looking at for def injection, but I can tell you that cylinder temps.(eventually egt) directly contribute to Nox levels. Higher temps.=higher Nox levels.
 
Swapped out the part earlier today, added a fresh DEF. I've put about 40 miles on it after changing the part and it is still showing the poor fluid quality message. Still no CEL, or any codes. The pump on top of the DEF tank seems to be running. I forgot to change one of the rubber washers between the pump and the tank heater module and it was leaking so I can only assume its building pressure. I pulled it back off and swapped the rubber washer and that cleared up the leak.

Its limited to 55mph now and I have about 50 miles before its limited to 4mph. I found this post here that says it may need to be driven up to 100 miles before it will clear the fault from the system. Anyone else that has had this issue have to drive that far before it cleared? I can drive it another 50 miles or so but if that does not fix it Ill be stuck to 4mph to get it anywhere. Not sure what to do from here...
 
95cummins5.9 said:
Look into deleting the junk.
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That was my first thought when this started but from the calls I've made about that I was told as of Oct the EPA cracked down on shops doing deletes on diesels. I haven't found anywhere that still sells the tune. I can find the down pipe, but fewer places are selling that.
 
Dropped it off at the dealer last week because I ran out of time to keep working on it myself. Got it back yesterday, 2 hours of labor for doing some diagnostic and the fault is cleared. Here is the wright up from the dealer


STATES POOR EXHAUST MESSAGE KEEPS COMING ON

P204C- RELUCTANT PRESSURE SENSOR CIRCUIT LOW VOLTAGE. THIS DTC IS IN A PASSED FAILED STATUS, THIS CODE IS NOT RELATED TO THE POOR QUALITY EXHAUST FLUID MESSAGE. THE TECHNICIAN CLEARED DTC, PERFORM A PRESSURE TEST AND THE SYSTEM PASSED. THE TECHNICIAN PERFORMED A EXHAUST FLUID QUALITY TEST, TEST PASSED AND THE MESSAGE WAS NO LONGER PRESENT. THE TECHNICIAN TEST DROVE THE VEHICLE, NO DTC'S RETURNED AND THE POOR EXHAUST FLUID MESSAGE IS NO LONGER PRESENT.


the P204C fault came up when I was checking the wiring going to the DEF tank heater module. I unplugged one of the wires when the car was running and it shut down and that code came up. I plugged it back in and after a few restarts the CEL went out. I did not clear the code because I was using the counter for "Miles driven from last reset" to keep up with how far I'd driven since last time Id cleared all the codes from swapping the DEF tank heater module. Only thing they could really say is that swapping the heater module just have fixed the issue but for some reason the fault did not clear until they did there testing. Spending $275 at the dealer for 2 hours of labor its a little upsetting but is a lot better that then 2k-3k I was expecting.

Thank you all for your input and help.
 
I swear they make vehicles in a way that makes stealerships unavoidable on purpose.My '02 is the newest vehicle I've ever purchased and I doubt that will ever change.
 
mhuggler said:
I swear they make vehicles in a way that makes stealerships unavoidable on purpose.My '02 is the newest vehicle I've ever purchased and I doubt that will ever change.
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I agree. Before this I was driving a 2003 Eclipse Spider GTS. Love that car. 260k and I've been able to fix any issues myself. Now the first thing you need is a laptop on newer vehicles anytime something goes wrong. Only reason I took over the cruze is I upgraded my wife to a newer toyota 4runner that she has wanted for a few years. Cant complain about the cruze 50+ mpg on my 150 mile a day commute.
 
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