# Miles between regen



## CruzeQC (Oct 3, 2020)

Hello,

I have a 2018 Cruze diesel hatchback with the 9sp auto trans. I live in eastern Canada. At this time of the year we get average 45F-50F temperatures through the day.
The car has about 50k miles (82 000km).
The car runs great, no MIL/CEL, strange sounds/vibrations, or anything.

I have a question regarding DPF regen miles. Today I installed a new ScanGauge II and programmed DPF X-Gauge codes to get RGN status (not working for some reason), STA (soot accumulation %) and ADR (Average distance ) and DSR (distance since last regen).

I love having that information at a glance. The thing is, STA and DSR are making me nervous. ADR is reporting 153 miles average. This seems very low to me. Today I went out for a spin and it did a Regen when the STA got to 59%. It went back to 0% in about 10 minutes on the Freeway, I was impressed how quick it was.

But then, STA started climbing really fast, I'd say, every one mile on DSR, one % was going up on STA. Went back home and it indicated 30 miles DSR, 33% STA. I'm getting nervous because it really seems abnormal to me.

Is there something I'm missing? Is it because the ScanGauge needs a calibration ? Should I change the Diesel(a) to Diesel(b)?

Car is running just normal to me, otherwise.

Thank you so much for your help


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## oregon_rider (Jul 21, 2017)

From what I have read here and what I have experienced myself - what you describe is normal behavior. It climbs up fairly quickly at first then plateau's off. 

For configuration - I picked some of the programming information for the 6 cylinder diesel chev colorado truck to get it things to work for me. Sorry it's been a while and I don't remember the specifics. I am displaying regen status now.

FWIW - if I saw 33% STA after 30 miles I would "feel good". No worries at all. 

And the fact that it regens to a low number in ten minutes would indicate to me that the DPF is in "very good conditon".

jeff


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## CruzeQC (Oct 3, 2020)

Thank you so much for your reply. I will try the V6 diesel Colorado code for RGN. 

33% STA after 30 miles seemed so much high % to me because I saw other posts here with numbers like 500-600-700 and even 800 miles Regen. I'm so far away from that with the numbers I get. But I suppose there's a lot of different factors in this equation...


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## BodhiBenz1987 (Jan 13, 2018)

What was DSR when your regen started? If it's going into regen at 59%, that usually means it has hit the distance limit (~800 miles). Otherwise it climbs to 100% before it regens. I'm guessing your average distance between figure is not right ... either because of the PID (ditto on trying the LWN/2.8L codes, they seem to work better), or the actual number stored by the car is wrong (not likely but mine is wrong as is total number of regens). As Jeff said your soot climb after a regen looks typical and not cause for worry. It should start stabilizing around 50%-60% ... as far as I understand the DPF needs to reach a certain "pack" level before it starts passively regenerating, hence the quick early climb is normal. I would add the LWN PIDs and keep monitoring DSR when each regen starts. I gave up on monitoring mine for the most part because it does regens all over the friggin map and GM won't let the dealer Dx or fix it unless there is a CEL, period. Mostly it's nice to keep an eye on trends, make sure it is actually completing them, and know when they are happening so I can try not to shut off during them.


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## CruzeQC (Oct 3, 2020)

Thanks for your reply! Unfortunately I programmed the DSR after the regen... I should have programmed it the same time I did STA, I guess I was excited to try the first custom gauge right away to see if it’s working fine!

What both of you say about plateau-ing and quick climb is very interesting. I think monitoring it will help me better understand the DPF behaviour...

I’ll try the Colorado PIDs instead!


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## CruzeQC (Oct 3, 2020)

Well I switched from the Cruze ADR code with 153 miles to the Colorado ADB code, it now indicates 775 miles. It sure makes more sense, I’ll see how it goes!


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## BodhiBenz1987 (Jan 13, 2018)

CruzeQC said:


> Well I switched from the Cruze ADR code with 153 miles to the Colorado ADB code, it now indicates 775 miles. It sure makes more sense, I’ll see how it goes!


Nice, it sounds like it's doing very well then. Your last regen was probably based on distance which is ideal, as it should passively regenerate any time you're on the highway and keep the soot in the 50s or so.


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## CruzeQC (Oct 3, 2020)

I didn’t know at all about the ~800 miles regen distance and the passive regen. This is very useful information.

Because of the current situation I don’t do as much highway as I was doing so I want to keep an eye on this DPF!

Thanks again!


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## MRO1791 (Sep 2, 2016)

CruzeQC said:


> Thank you so much for your reply. I will try the V6 diesel Colorado code for RGN.
> 
> 33% STA after 30 miles seemed so much high % to me because I saw other posts here with numbers like 500-600-700 and even 800 miles Regen. I'm so far away from that with the numbers I get. But I suppose there's a lot of different factors in this equation...


It is the Colorado 2.8L Diesel I-4 that you want, the V6 is a gasoline engine. The 2.8L Duramax shares the same PIDs with the 1.6L Diesel. 

The soot always climbs fast early on, then slows way down. Up to about 60 on soot and about 60 miles is not unusual. then it gets many miles for each increase in soot, think reverse exponential on this one, not linear. 

Miles between regens can vary significantly. The drive patterns make a big difference, and even the specific parameters of the engine and transmission, and fuel quality. I can see it in my family fleet of 3 Gen 2 Diesels, and one Gen 1 Diesel. I've noted the automatic cars go longer between regens than the manual, and my guess is the lower final drive ratio of the 9sp is the biggest difference.


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## CruzeQC (Oct 3, 2020)

I went for another spin yesterday on the highway because I was curious how it would go. Sure enough it did what you are saying: it continued climbing up to 45% STA, then it slowly started going down to 38%, then slowly back up... So it seems this is the passive Regen. During this time the Colorado RGS PID (Regen Status) was still showing "0". 



MRO1791 said:


> Miles between regens can vary significantly. The drive patterns make a big difference, and even the specific parameters of the engine and transmission, and fuel quality. I can see it in my family fleet of 3 Gen 2 Diesels, and one Gen 1 Diesel. I've noted the automatic cars go longer between regens than the manual, and my guess is the lower final drive ratio of the 9sp is the biggest difference.


The factors for my Cruze are very stable: 140 miles commute, 95% highway, always been filling up at the same gas station except maybe a few exceptions.

You have 3 Gen 2 Cruze TD! That's impressive. Just a quick question, because I don't want to be too off topic: what do you think of the 9sp automatic trans? So far it's been doing great in mine. At first I though it was kind of harsh (not sure how to say this in english), "jerking" at low speed, but it eventually got better. I changed the oil at 80k KM because I don't trust the life-time thing. 

Thank you!


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## MRO1791 (Sep 2, 2016)

CruzeQC said:


> I went for another spin yesterday on the highway because I was curious how it would go. Sure enough it did what you are saying: it continued climbing up to 45% STA, then it slowly started going down to 38%, then slowly back up... So it seems this is the passive Regen. During this time the Colorado RGS PID (Regen Status) was still showing "0".
> 
> 
> 
> ...


The 9sp is a massive improvement over the Gen 1 6 speed unit, which was known for some strange shift patterns. I have never noticed any harshness in the two 9sp Gen 2s in the family fleet.. but you are correct, there is NO LIFETIME fluid out there, I already have begun to purchase the parts and tools to do fluid and filter changes for these when they come due, the Gen 1 auto fluid was super dark and thin when changed at 45K miles, no way that is lifetime, and it had noticeable better shifts with the new fluid as well. I'm expecting similar change interval on the 9sp, though it does run much, much cooler than the Gen 1 6sp, so it might be easier on the fluid as a result. 

All that said, I have seen a couple of people have problems with the new 9sp, and it's a low production item, so time will tell if that is a trend or just isolated incidents.


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