# CEL illuminated 65 miles before warranty lapses...



## Barry Allen (Apr 18, 2018)

Just today the CEL is on and it's now 65 miles before the powertrain warranty lapses on the car. Two notable codes:
P20EE - NOx Catalyst Efficiency Below Threshold Bank 1
P11DB - NOx Sensor Current Performance Bank 1 Sensor 1

Obviously some funny business with the NOx catalyst and/or sensors is going on.

I had run the DEF tank down to about 15% capacity because I like to run it almost empty before I refill. I had wondered if the DEF was somehow going stale, but I remember that the car gives a dashboard warning if the DEF quality is sensed to be less than acceptable. Just to see what happens, I filled it up with a fresh 2.5 gallon container from AutoZone after I pulled the OBD codes from the computer.

I've got an appointment with the dealership on Monday after work and the service writer (I'm on a first name basis with Derrick - when I called and said "Hey, it's Aaron..." he asked "What is broken now?) and they say it's no problem and the warranty will be honored because I've got a photograph of the CEL and the odometer.

Anyone have any thoughts?


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## Barry Allen (Apr 18, 2018)

After reading the warranty booklet, it appears I might have longer warranty coverage under the federal emissions system warranty: _"8 years or 80,000 miles for the catalytic converter, vehicle/ powertrain control module, transmission control module or *other onboard emissions diagnostic device*, including emission-related software, whichever comes first."_

NOx sensors are listed in the warranty booklet as "Diesel Exhaust Aftertreatment Actuators and Sensors."


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## JLL (Sep 12, 2017)

Barry Allen said:


> (I'm on a first name basis with Derrick - when I called and said "Hey, it's Aaron..." he asked "What is broken now?)


Being a former service advisor myself, That's not a good statement. 😔

I'm glad their getting you taken care of.


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## Barry Allen (Apr 18, 2018)

JLL said:


> Being a former service advisor myself, That's not a good statement. 😔


I was with my mom in the car when I called. She blurted out: “The mechanic knows you by first name?!”


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## jblackburn (Apr 14, 2012)

Barry Allen said:


> I was with my mom in the car when I called. She blurted out: “The mechanic knows you by first name?!”


Sounds like my old Volvo mechanic


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## Barry Allen (Apr 18, 2018)

I'm still waiting to hear about the diagnosis, but I suspect just a bad NOx sensor. 

The dealership had it this afternoon to diagnose the problem with a clear agreement that they would give the car back to me before they closed so I could go to work tomorrow while a part is ordered (if that's what the fix is). I finally called to ask what is going on and the service department was closed. I had to take an Uber there and make one of the sales managers go get my car out of the shop because I start work at 4am when there is no bus, no Uber drivers, and not even a taxi driver out at that hour.

Will see what they say tomorrow. You know, other than "Sorry" for not getting the car back to me.


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## Barry Allen (Apr 18, 2018)

I guess I'm mistaken about the emissions warranty. The phrase "other onboard emissions diagnostic device" applies to the ECU, TCU, or other computer chip that does the actual emissions monitoring and control of the powertrain to comply with emissions. Sensors are not "diagnostic devices" for the purpose of the 80,000 mile warranty.

I have until 60,288 miles for the warranty and the dealership has ordered a part. They are "holding the ticket open" even though I took the car to drive because that's how it's covered under warranty, but if the part isn't here prior to this weekend I will have things to do that will easily push the car past the mileage limit. I can't wait to see what kind of argument that is.


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## Barry Allen (Apr 18, 2018)

When I picked my car up from the dealership I did notice the technician (or someone else) drove it for about 12 miles. I assume they took the car out to warm it up and test the NOx sensor when it was running at temperature.

They didn't say or ask anything about the DEF. I haven't got any warning messages about low quality DEF, and the same day the light was on I filled with fresh DEF and drove it for the weekend so the car has had time to get fresh DEF running through the emissions system if that were the problem.


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## Barry Allen (Apr 18, 2018)

Does this sensor being bad affect fuel economy? I'm noticing a substantial decrease of highway fuel economy, and I'm wondering of the ECU tunes the engines to reduce NOx emissions at the expense of fuel economy when there is a bad sensor.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> Does this sensor being bad affect fuel economy? I'm noticing a substantial decrease of highway fuel economy, and I'm wondering of the ECU tunes the engines to reduce NOx emissions at the expense of fuel economy when there is a bad sensor.


No.


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## boraz (Aug 29, 2013)

Barry Allen said:


> Just today the CEL is on and it's now 65 miles before the powertrain warranty lapses on the car. Two notable codes:
> P20EE - NOx Catalyst Efficiency Below Threshold Bank 1
> P11DB - NOx Sensor Current Performance Bank 1 Sensor 1
> 
> ...


the car has no idea if the def is fresh or stale


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## Barry Allen (Apr 18, 2018)

boraz said:


> the car has no idea if the def is fresh or stale


Oh yeah?


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> No.


It seems to be quite the coincidence that my highway fuel economy plunged 20% after this CEL is illuminated.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> Oh yeah?
> 
> View attachment 292391


The science doesn’t really support it.
For the sensor to kick off the refractive index would have to change pretty drastically. Kind of up in the air how much that is but it’s in the whole percentage points of Urea to water. That’s extremely tolerant of any decomposition.

And said decomposition would hypothetically take like 2 to 3 years to start taking the DEF out of spec. Which would more or less be from the def sitting on the shelf in your garage. Or in the tank. But again the sensor in the tank isn’t near good enough to notice this. This would occur much more rapidly if allowed to sit in sunlight buuut it’s still order of months.

The kicker is the decomposition doesn’t even matter. It’s turning the urea into Ammonia and CO2. Both of which will just enter the solution…

And here’s the double kicker. That above solution is actaully a more effective SCR agent than normal Normal Urea DEF. The only reason we don’t use ammonia solution is because ammonia is dangerous. And Meth.

In other words…. DEF actually gets better as it ages. What does happen is the longer you keep it around the greater the chance of something else getting in and causing havoc. Metal contaminants are the worse.


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## Snipesy (Dec 7, 2015)

And I said it before but I have fixed 100 trucks with this quality poor issue.

Not one has had bad DEF. Not even contaminated DEF. it’s a fallacy pushed by GM. Another case of “We obviously make infallible systems sooo obviously it can’t be _*Our* system that is malfunctioning”._

I even work with heavy machines on occasion which go through DEF in stupid quantities. Again not once has there been a problem with DEF quality.


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## Barry Allen (Apr 18, 2018)

I assume the error message is for when cheapskates pour water into the tank and the sensors can obviously detected that it is doing nothing for NOx reduction.


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## boraz (Aug 29, 2013)

Snipesy said:


> And I said it before but I have fixed 100 trucks with this quality poor issue.
> 
> Not one has had bad DEF. Not even contaminated DEF. it’s a fallacy pushed by GM. Another case of “We obviously make infallible systems sooo obviously it can’t be _*Our* system that is malfunctioning”._
> 
> I even work with heavy machines on occasion which go through DEF in stupid quantities. Again not once has there been a problem with DEF quality.


ive been trucking since the 90s

watched all the def/dpf/scr get introduced

last company i worked at had deleted fleet, current company is deleted fleet, my cruze is deleted

ive yet to meet a mechanic that has found bad def, cuz the def is never bad

early on, companies and mechanics bought refractors, nobody has em any more


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## boraz (Aug 29, 2013)

Barry Allen said:


> Oh yeah?
> 
> View attachment 292391


sigh

the bad def light comes on cuz the computer doesnt like the post scr readings

so it assigns blame to the def quality

there is no def quality sensor


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## pandrad61 (Jul 8, 2015)

boraz said:


> ive been trucking since the 90s
> 
> watched all the def/dpf/scr get introduced
> 
> ...


A whole deleted fleet, not that company better pray they don’t get caught


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## MP81 (Jul 20, 2015)

pandrad61 said:


> A whole deleted fleet, not that company better pray they don’t get caught


Canada. Don't think their EPA-equivalent has such a hardon for deleted diesels, as they don't have a Diesel Bros Eh? showcasing a bunch off assholes doing stupid **** and ruining it for the rest of us.


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## Barry Allen (Apr 18, 2018)

MP81 said:


> Diesel Bros


The Bros' complaints about why they delete engines they build are/were legitimate. We have diesel emissions equipment that basically destroys engines - EGR clogs intakes with soot and causes all kinds of problems.

I'm not opposed to DPFs on engines to catch soot, and I'm not opposed to SCR to reduce NOx. The EGR that feeds soot right back into the intake is the worst problem and should be eliminated if any user can do so.


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## MP81 (Jul 20, 2015)

Barry Allen said:


> The Bros' complaints about why they delete engines they build are/were legitimate. We have diesel emissions equipment that basically destroys engines - EGR clogs intakes with soot and causes all kinds of problems.
> 
> I'm not opposed to DPFs on engines to catch soot, and I'm not opposed to SCR to reduce NOx. The EGR that feeds soot right back into the intake is the worst problem and should be eliminated if any user can do so.


Totally agreed - the systems work...but not real well. As you mention, the EGR is easily the worst part of the system. If they didn't have that, perhaps less system issues would be present.

However, the Diesel Bros also run around rolling coal like a bunch of douchebags. When you cut cats off a car, you generally don't run around screaming that you're catless. Attention is not something you should want...but attention is what they got...and the rest of us pay the price.


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## pandrad61 (Jul 8, 2015)

MP81 said:


> Canada. Don't think their EPA-equivalent has such a hardon for deleted diesels, as they don't have a Diesel Bros Eh? showcasing a bunch off assholes doing stupid **** and ruining it for the rest of us.


Ahh that’s different. Yah **** those diesel dicks. Because they think rolling coal is cool the performance gas and diesel market is in the crosshairs.


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## Barry Allen (Apr 18, 2018)

MP81 said:


> EGR is easily the worst part of the system. If they didn't have that, perhaps less system issues would be present.


I had always asked myself why exhaust gas wasn't diverted after the DPF, then fed into the intake. If you do that you have filtered out most of the soot (no DPF is flawlessly perfect) so you've eliminated most of the problem.

GM has done that in the new 3.0 Duramax inline six engine for their 1500 pickups and SUVs. I'm eagerly awaiting the results of that.

Even with that advancement, however, I think Diesel engines for passenger cars are largely finished. VW screwed that up and no one wants to make them any longer. The move to EVs will accelerate and end future development of Diesel engines for anything other than trucks and SUVs.


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## pandrad61 (Jul 8, 2015)

Barry Allen said:


> I had always asked myself why exhaust gas wasn't diverted after the DPF, then fed into the intake. If you do that you have filtered out most of the soot (no DPF is flawlessly perfect) so you've eliminated most of the problem.
> 
> GM has done that in the new 3.0 Duramax inline six engine for their 1500 pickups and SUVs. I'm eagerly awaiting the results of that.
> 
> Even with that advancement, however, I think Diesel engines for passenger cars are largely finished. VW screwed that up and no one wants to make them any longer. The move to EVs will accelerate and end future development of Diesel engines for anything other than trucks and SUVs.


I hate to think that way but yes, diesel is a dying breed in anything other then HD trucks and heavy industries. **** VW for really putting the nail in the coffin.


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## Snipesy (Dec 7, 2015)

boraz said:


> sigh
> 
> the bad def light comes on cuz the computer doesnt like the post scr readings
> 
> ...


You are right. There is no quality sensor.

They use the level sensor. Which is a small radar or ultrasonic sensor... To measure the quality.

It doesn’t work. At all. But the companies who made the def system were trying to be cute and use an all in one solution. Money? I don’t know. All I know Is the sensor is unreliable and not even the ECM really gives a s*** about it.
Newer trucks have dedicated quality sensors now.


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## boraz (Aug 29, 2013)

pandrad61 said:


> A whole deleted fleet, not that company better pray they don’t get caught


previous company was 75,000 acre private site coal mine, all off road

no laws apply

current company is tanker for the oil patch in alberta

alberta dont care



http://www.transportation.alberta.ca/Content/docType41/Production/CVIManual.pdf



scroll down to page 27 for lols


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## MP81 (Jul 20, 2015)

That's funny right there. It would only be funnier if they had chosen to physically write "MEH" instead.


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## Snipesy (Dec 7, 2015)

MP81 said:


> That's funny right there. It would only be funnier if they had chosen to physically write "MEH" instead.


‘Deletes are rampant in the trucking industry. You can usually perform the delete using OEM software. Usually just configuring it for another country.

The support line will even help you do that.


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## MP81 (Jul 20, 2015)

Snipesy said:


> ‘Deletes are rampant in the trucking industry. You can usually perform the delete using OEM software. Usually just configuring it for another country.
> 
> The support line will even help you do that.


That's awesome, and at the same time it isn't. The reduction in diesel emissions from a semi would be far more impactful than worrying about 5 people trying to delete the emissions on their consumer vehicles. Similar to the EPA trying to focus on aftermarket performance parts all together...because that's not an infinitesimally small percentage compared to all vehicles on the road...


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> ‘Deletes are rampant in the trucking industry. You can usually perform the delete using OEM software. Usually just configuring it for another country.


Interesting.

What countries have cars using the GM Medium Diesel Engine without DPF and SCR? Might it be as easy as buying an ECU from one of those countries and putting it in a Cruze here to delete/tune the engine?


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> Interesting.
> 
> What countries have cars using the GM Medium Diesel Engine without DPF and SCR? Might it be as easy as buying an ECU from one of those countries and putting it in a Cruze here to delete/tune the engine?


GM doesn’t do it. Because they would be scrutinized. And this is just a flaw in that passenger car companies get all the blame while emitting less emissions overal.

The offenders I know of are...
All of Cummins. Including RAM. They have yet to be fined but IMOP it’s a blatant violation that is much bigger than VW scandal.
DDC. Which yea at one point was GM but not anymore. So freightkiner, international...

Probably more but I mean what that makes up more than half the industry already.


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## Snipesy (Dec 7, 2015)

Not to mention all the marine and locomotive engines the above manufactures make.


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## Barry Allen (Apr 18, 2018)

Snipesy said:


> Not to mention all the marine and locomotive engines the above manufactures make.


Modern locomotives are Tier 4 compliant. The huge emissions problem is all the locomotives that are 30+ years old and continuing to run, with engine rebuilds done on blocks that have the original build plate so they are largely exempt from emissions and never have to upgrade.


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## Snipesy (Dec 7, 2015)

Barry Allen said:


> Modern locomotives are Tier 4 compliant.


Before or after they go across the pond?

The real issue is other countries don’t give a *** and we happily exploit that. Why do you think no one registers their vessel in the USA? Just by changing a flag you completely bypass the EPA the Second you leave port.

Many of these vessels are brand new and are still burning bunker fuel. Where do you think those engines come from?

Its not rocket science. But like the rest of US Policy “Out of sight, out of mind” means “I don’t care“. Except it does. Because a country polluting on the opposite side of the world affects us. Here. Yes even your remote cabin in Montana.

The above reason is frankly why I don’t care if people delete cause we have bigger problems at play. And if that means threatening war with countries so be it cause it’s going to be what is necessary within our life time.


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## Cruz15 (Mar 17, 2016)

Barry Allen said:


> The Bros' complaints about why they delete engines they build are/were legitimate. We have diesel emissions equipment that basically destroys engines - EGR clogs intakes with soot and causes all kinds of problems.
> 
> I'm not opposed to DPFs on engines to catch soot, and I'm not opposed to SCR to reduce NOx. The EGR that feeds soot right back into the intake is the worst problem and should be eliminated if any user can do so.


Egr is the main problem with Diesel engines. DPFs catch soot to get burned off to be made into even finer particles, much easier to be stuck in the deepest reaches of peoples lungs.
My 2015 had the DEF message, they tested my def there was no problem they cleaned the system and sent me home with fresh DEF, when it happened again they replaced the whole DEF system according to GMs instructions. The system was the problem. I dont see a problem with DEF systems as long as they function correctly.


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## Barry Allen (Apr 18, 2018)

Hah, replacing the NOx sensor did not fix the problem. The service adviser says the technician needs to diagnose it more tomorrow. I picked the car up to go to work tomorrow and the CEL is off, so it makes me curious how that "didn't fix the problem" if the light is off.


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## Barry Allen (Apr 18, 2018)

Notes from the technician when I picked the car up today:

*FOUND P20EE AND P11DB FOUND IN ECM. TEST DROVE AND FOUND NOX 1 TO BE READING NORMAL VALUES AT THIS TIME. SUSPECT INTERMITTENT CONCERN. AFTER REPLACEMENT OF NOX SENSOR, P2628 SET IN ECM AS PASSED AND FAILED AFTER 2 TEST DRIVES. DTC IS FOR INTERNAL MALFUNCTION WITH SENSOR AND ARE INSTRUCTED TO REPLACE NOX SENSOR IF DTC IS CURRENT. CLEARED DTC AND TEST DROVE, NO DTCS AT THIS TIME. NORMAL DRIVEABILITY.*

So, it appears the NOx sensor threw a CEL that was no longer any problem by the time the technician first diagnosed it. I have no idea if this goes back to the quality of the DEF in the tank, because I mentioned it was down to about 15% when I filled it up with fresh DEF. They ordered the sensor, replaced it, and apparently the new P2628 code showed up (but no CEL illuminated) as a pass and fail in separate test drives.

The service advisor is leaving the ticket open for about a week for me to drive and see if the CEL returns or anything else happens.


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## MP81 (Jul 20, 2015)

About...two NOx2 sensors ago...it would occasionally throw a CEL, which would go away on its own. Come back, go away, but never really caused a problem, and never caused a countdown. The only reason I replaced it was because the Particulate sensor took a **** and caused a countdown. That was replaced under the special coverage that exists on the 1st gen cars...but it could never complete the test required to remove the countdown, because of the NOx2 sensor throwing a code.


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