# P24C6 code



## Scott M. (Apr 23, 2013)

Further googling shows nissan has the same code for particular matter sensor temperature circuit. the car does have a particular matter sensor so maybe thats it.


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## 2013LT (Jul 3, 2013)

I'm digging deep for you here... Haven't come up with anything but I'm excellent in googling give me a few minutes


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## 2013LT (Jul 3, 2013)

So far I've found what you already know... The first four characters are this:

Generic Auxiliary Emission Control System


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## 2013LT (Jul 3, 2013)

Nope I can't find it as hard as I tried. I even went through the European diesel manual but it looks like their systems there don't have the DEF therefore the code isn't in there (Figures). Good luck hopefully a GM tech sees this and lets you know what the code is. However if you were to get the code reset I bet you it wouldn't come back.


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## obermd (Mar 3, 2012)

Scott M. said:


> Further googling shows nissan has the same code for particular matter sensor temperature circuit. the car does have a particular matter sensor so maybe thats it.


A lot of the ODBII codes have been standardized across manufacturers.


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## 5 O'Clock Charlie (Oct 24, 2013)

The way I read it you have the P24C6 code with no other codes then your exhaust particulate matter sensor is out of tolerance ......















Hope this helps !

ccasion14:


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## Scott M. (Apr 23, 2013)

Thanks ! This forum is great. On the way into work I again got the exhaust fluid poor message and countdown after 20 miles since resetting. I was passing by my dealer anyway so I popped in and left with a loaner Chevy Captiva. Looks like I will be getting a new particulate matter sensor. I thought that was just for monitoring health of the DPF. I dont know if the two problems are related. I am going to make them drive the car for 30 miles after reset to see if its really fixed.


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## diesel (Jun 8, 2013)

Scott M. said:


> Thanks ! This forum is great. On the way into work I again got the exhaust fluid poor message and countdown after 20 miles since resetting. I was passing by my dealer anyway so I popped in and left with a loaner Chevy Captiva. Looks like I will be getting a new particulate matter sensor. I thought that was just for monitoring health of the DPF. I dont know if the two problems are related. I am going to make them drive the car for 30 miles after reset to see if its really fixed.


I am curious if it's just the sensor. A couple other people have had a similar message but I don't recallwhat the root cause was. Keep us posted!


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## 5 O'Clock Charlie (Oct 24, 2013)

I'm curious as to the outcome of this problem as well .....

After doing a bit of reading, it seems to me the particulate matter sensor fault (P24C6) should be unrelated to the exhaust fluid quality message. As stated is the manual I copied earlier the P24C6 code is caused by the particulate matter sensor temperature being out of tolerance, but the 'exhaust fluid low quality' message is generated by a comparison of upstream and downstream NOx sensors not showing enough NOx reduction across the SCR (Selective Catalyst Reduction) ...... meaning the DEF fluid is weak.

I can't figure how they're related ......

:dizzy::dazed002:


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## diesel (Jun 8, 2013)

5 O'Clock Charlie said:


> The way I read it you have the P24C6 code with no other codes then your exhaust particulate matter sensor is out of tolerance ......
> 
> View attachment 101889
> View attachment 101897
> ...


Is that from the Helm manual? I stillwant to buy one of those.


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## 5 O'Clock Charlie (Oct 24, 2013)

diesel said:


> Is that from the Helm manual? I stillwant to buy one of those.


Yes. My Cruze CTD is my first new car, and I've been fixing my own cars for 30 years so I felt kind of naked and vulnerable without a good manual !! Fortunately my CTD has been reliable as heck, and I haven't had to do a darn thing too it. I just had my third free oil change so I am looking forward to doing my own when the freebies run out !

As for the Helm manual, I'd give it a thumbs up ...... It covers all the Cruze variants, but there is plenty of diesel info in there. It comes in 5 volumes and fairly well indexed, but obviously written for GM techs who have access to all the correct tools etc. but LOTS of good info regardless.


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## diesel (Jun 8, 2013)

5 O'Clock Charlie said:


> Yes. My Cruze CTD is my first new car, and I've been fixing my own cars for 30 years so I felt kind of naked and vulnerable without a good manual !! Fortunately my CTD has been reliable as heck, and I haven't had to do a darn thing too it. I just had my third free oil change so I am looking forward to doing my own when the freebies run out !
> 
> As for the Helm manual, I'd give it a thumbs up ...... It covers all the Cruze variants, but there is plenty of diesel info in there. It comes in 5 volumes and fairly well indexed, but obviously written for GM techs who have access to all the correct tools etc. but LOTS of good info regardless.


Excellent, thanks!


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## boraz (Aug 29, 2013)

on our work trucks with dpf's code will come up low def quality

there is no sensor measuring the quality of the def on the truck whatsoever.

the computer notices poor nox conversion, the mechanic then verifies the def quality with a refractor dealiebob, if it checks out, the issue is in the dpf itself....if there is an actual issue, or just a bad sensor, wire, harness etc....signalling the computer


I HAVE ZERO IDEA IF THE CRUZE ACTUALLY HAS A DEF QUALITY SENSOR, guessing no, guessing its similar to what i described.

GUESSING


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## diesel (Jun 8, 2013)

boraz said:


> on our work trucks with dpf's code will come up low def quality
> 
> there is no sensor measuring the quality of the def on the truck whatsoever.
> 
> ...


Interesting theory and it sounds likely to me that the Cruze would not check the fluid itself, but instead check the anticipated result of what it does.


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## Scott M. (Apr 23, 2013)

Update. The dealer is doing what they do best. Deflecting from the problem. The particulate matter sensor hard failed and they changed it. Good job with that simple task. That sensor has nothing at all to do with the DEF quality poor message. For that they followed their playbook and told me that the DEF fluid I bought at the advanced auto store is bad and I need to use AC delco fluid. They drained flushed and tested the fluid and charged me 45 bucks for their fluid. I picked up the car and said "see you tomorrow" sure enough 30 miles later the message came back on. I took it back and got a loaner car. Now they will likely change the whole DEF tank and pump but that is not the problem either. Then I suppose they will try to blame it on bad fuel. When they exhaust all the options that don't involve them thinking, they might actually do something to fix the car like reprogram the computer to raise the tolerances .


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## Tomko (Jun 1, 2013)

There's so little service history on the emissions control system of this engine that it's almost a process of elimination from the service technician's perspective. So the first thing they do is try to address the variables that aren't under their immediate control like DEF and fuel quality. One of the realities of being an early adopter. 

But please keep us informed and don't loose faith.


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## Scott M. (Apr 23, 2013)

True. It is good judgement to rule out the simple stuff first but to say that the DEF fluid at the wal mart is any different than the DEF fluid at the GM dealer is a bit much to swallow. DEF is just Urea and water. Nothing magical or mystical about it and this is a common problem on the diesel silverados too so they should be better equipped to handle it. Currently driving a cruze with 400 miles on it so I should be happy about that.


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## boraz (Aug 29, 2013)

diesel said:


> Interesting theory and it sounds likely to me that the Cruze would not check the fluid itself, but instead check the anticipated result of what it does.


correct


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## diesel (Jun 8, 2013)

Definitely keep us posted


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## Scott M. (Apr 23, 2013)

Still in the shop. They changed the downstream NOX sensor. That didn't solve the problem either. They are scratching their heads now. They will probably just carpet bomb the problem with a whole new exhaust system. I think the the system is just not capable of achieving the levels it is trying to get. ULSD is 15 PPM sulfur and the system is trying to make it even lower. How can anything be that accurate ? If you get a bad tank of diesel that has 20 parts per million of sulfur the system may not be able to handle it. Who knows for sure ? Not me and unfortunately not GM. The emission systems are the weak link to the modern diesels.


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## Scott M. (Apr 23, 2013)

Update. Got some encouraging news. The dealer says they removed the DEF injector and the injector nozzle was clogged and the spray pattern was insufficient. This is a plausible explanation for the exhaust fluid quality poor message. DEF fluid does get hard an crusty when it dries and the car sat unused in the body shop for 2 weeks after the encounter with the deer. I notice the white crud around the fill port after it dries up. They are installing the part tomorrow then they have to test it.


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## boraz (Aug 29, 2013)

Scott M. said:


> Update. Got some encouraging news. The dealer says they removed the DEF injector and the injector nozzle was clogged and the spray pattern was insufficient. This is a plausible explanation for the exhaust fluid quality poor message. DEF fluid does get hard an crusty when it dries and the car sat unused in the body shop for 2 weeks after the encounter with the deer. I notice the white crud around the fill port after it dries up. They are installing the part tomorrow then they have to test it.


nice.

wouldve been nicer for them to have checked def flow already

if the conversion isnt happening, you gotta eliminate the easy, def quality and def flow...if those are good your box is dead, on our trucks thats 10grand

flow is easy to test, pump into a container, so many ml's per min

if flow is not good, check the pump, metering valve, def air regulator, plv


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## Scott M. (Apr 23, 2013)

Failed again. I picked up the car after they changed the DEF injector. They claimed they test drove the car but the message came on 30 miles later same as always. took it back at got the gas engine cruze loaner back. They think they are doing me a favor giving me a car that gets 10 miles less per gallon


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## Jim Frye (Mar 16, 2011)

Well, at least the loaner won't throw a P24C6 code. :1poke:


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## Scott M. (Apr 23, 2013)

Ha, too right. Its times like this when the cheap little gasser looks allot better. But I forget all to fast when I am getting 46 MPG. Hope it gets sorted out soon. The car ran for 47,000 miles with no trouble. Hopefully I can go at least another year without problems.



Jim Frye said:


> Well, at least the loaner won't throw a P24C6 code. :1poke:


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## boraz (Aug 29, 2013)

Scott M. said:


> Thanks ! This forum is great. On the way into work I again got the exhaust fluid poor message and countdown after 20 miles since resetting. I was passing by my dealer anyway so I popped in and left with a loaner Chevy Captiva. Looks like I will be getting a new particulate matter sensor. I thought that was just for monitoring health of the DPF. *I dont know if the two problems are related.* I am going to make them drive the car for 30 miles after reset to see if its really fixed.


the dpf wont work without the def


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## boraz (Aug 29, 2013)

5 O'Clock Charlie said:


> I'm curious as to the outcome of this problem as well .....
> 
> After doing a bit of reading, it seems to me the particulate matter sensor fault (P24C6) should be unrelated to the exhaust fluid quality message. As stated is the manual I copied earlier the P24C6 code is caused by the particulate matter sensor temperature being out of tolerance, but the 'exhaust fluid low quality' message is generated by a comparison of upstream and downstream NOx sensors not showing enough NOx reduction across the SCR (Selective Catalyst Reduction) ...... meaning the DEF fluid is weak.
> 
> ...


dpf needs def to function


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## boraz (Aug 29, 2013)

Scott M. said:


> Update. The dealer is doing what they do best. Deflecting from the problem. The particulate matter sensor hard failed and they changed it. Good job with that simple task. That sensor has nothing at all to do with the DEF quality poor message. For that they followed their playbook and told me that the DEF fluid I bought at the advanced auto store is bad and I need to use AC delco fluid. They drained flushed and tested the fluid and charged me 45 bucks for their fluid. I picked up the car and said "see you tomorrow" sure enough 30 miles later the message came back on. I took it back and got a loaner car. Now they will likely change the whole DEF tank and pump but that is not the problem either. Then I suppose they will try to blame it on bad fuel. When they exhaust all the options that don't involve them thinking, they might actually do something to fix the car like reprogram the computer to raise the tolerances .


is there an actual def quality sensor?

or are they seeing poor conversion in the dpf and working backwards?


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## grs1961 (Oct 23, 2012)

boraz said:


> dpf needs def to function


Does it? Really?

My DPF works quite well without DEF, as do many, many other diesel vehicles.

And if GM USA have been foolish enough to link the DPF system to the DEF system, they should be shot, it is an unnecessary interdependence.


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## 5 O'Clock Charlie (Oct 24, 2013)

boraz said:


> dpf needs def to function


I believe your incorrect. The DEF gets injected downstream of the DPF and has no effect on it ..... the DEF is used in the SCR.


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## 5 O'Clock Charlie (Oct 24, 2013)

boraz said:


> is there an actual def quality sensor?
> 
> or are they seeing poor conversion in the dpf and working backwards?


They are measuring a drop in Nox across the SCR ( selective catalyst reduction) via a pre and post Nox sensor.


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## boraz (Aug 29, 2013)

grs1961 said:


> Does it? Really?
> 
> My DPF works quite well without DEF, as do many, many other diesel vehicles.
> 
> And if GM USA have been foolish enough to link the DPF system to the DEF system, they should be shot, it is an unnecessary interdependence.





5 O'Clock Charlie said:


> I believe your incorrect. The DEF gets injected downstream of the DPF and has no effect on it ..... the DEF is used in the SCR.


ya i worded it completely wrong

this emissions system is designed to use the def, yours and others are designed to not use it and use more egr to get the same end result

on our trucks its one big box that has all the emissions stuff and all the sensors are right there, but its different components and it goes thru a maze of pipes to do its thing

i dont have the cruze system in my head yet


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## 5 O'Clock Charlie (Oct 24, 2013)

Yeah, it's a pretty complicated system ..... I bought a set of the manuals, mostly because I hate not knowing how something works and so I can't get bullshited at the dealer. But luckily 11 months and 34000 km without a snag !

Here's a snapshot of all the components in the exhaust system.


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## Scott M. (Apr 23, 2013)

Great picture. Thanks. We do not have an ammonia sensor to determine DEF quality. If the Nox sensors dont see the results they are looking for they assume we are putting straight water in the system and starts the countdown to death.


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## suzdar ismaill (Sep 26, 2020)

[QUOTE = "Scott M. ، post:He also has the same story of how the repair was done


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## suzdar ismaill (Sep 26, 2020)




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