# def and regen cycle questions



## mr overkill (Dec 1, 2013)

So I'm at 11,800 and I have yet for the regeneration light to go on yet I am using urea. Does urea get used in normal driving and a regen only on heavy usage


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## jblackburn (Apr 14, 2012)

You should normally not notice a regen, and the car won't tell you it's doing it unless you cut it off in the middle of a regen cycle several times, in which case you may get a "keep driving" message. If you ignore that, the dealer may have to manually force a regen when the car goes into its emissions limp mode.

Urea injection is always used, as is the diesel particulate filter. The two systems work in tandem to meet strict emissions requirements.


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## revjpeterson (Oct 2, 2013)

The regen light on the instrument cluster is not functional on the North American Cruze. The regens occur "silently," and can only be detected by the drop in fuel economy, possibly a fan running after shutting down the engine (although this can happen for other reasons too), or an odor from protective layers burning off of the exhaust during the first few regens after new. If too many regens are interrupted, you may see the "keep driving" message mentioned above, but otherwise there is no instrument panel indication that a regen is occurring and no intervention needed.

DEF injection occurs at all times the engine is running and is unrelated to regen cycles. The two systems (DPF and DEF) are parallel methods which serve to eliminate different components of diesel exhaust (soot and NOX).


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## boraz (Aug 29, 2013)

revjpeterson said:


> The regen light on the instrument cluster is not functional on the North American Cruze. The regens occur "silently," and can only be detected by the drop in fuel economy, possibly a fan running after shutting down the engine (although this can happen for other reasons too), or an odor from protective layers burning off of the exhaust during the first few regens after new. If too many regens are interrupted, you may see the "keep driving" message mentioned above, but otherwise there is no instrument panel indication that a regen is occurring and no intervention needed.
> 
> DEF injection occurs at all times the engine is running and is unrelated to regen cycles. The two systems (DPF and DEF) are parallel methods which serve to eliminate different components of diesel exhaust (soot and NOX).


what he said


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## revjpeterson (Oct 2, 2013)

Oh, and regens occur approximately every 500-800 miles (give or take another hundred for extreme driving conditions), depending on the amount of soot you are producing, so you have definitely experienced multiple regens in your nearly 12,000 miles. The computer triggers regen cycles based on readings from differential pressure sensors on either side of the DPF. When the pressure upstream of the DPF reaches a certain threshold higher than the pressure downstream of the DPF, the regen cycle burns off the accumulated soot from the DPF.


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## mr overkill (Dec 1, 2013)

ok that makes scene i just thought it was weird but if i get a monitor i will be able to see soot levels and see when it "drops" i found that torque pro app


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## boraz (Aug 29, 2013)

mr overkill said:


> ok that makes scene i just thought it was weird but if i get a monitor i will be able to see soot levels and see when it "drops" i found that torque pro app


yep youll be able to monitor soot, http://www.cruzetalk.com/forum/201-.../81417-observations-edge-insight-monitor.html

with torque pro?, i have no idea


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## revjpeterson (Oct 2, 2013)

I use Torque Pro, and I can monitor several pieces of data from my Diesel. Right now, though, the soot level PID is not programmed into Torque Pro, because it is just using the universal PID set. But if you can find it and program it yourself as a user-defined PID or if someone builds a plugin with a CTD-specific PID set for TorquePro that you can download (as exist for some other vehicles), then you could monitor it with TorquePro.


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## knronald (Oct 14, 2014)

My car is now 1 month old and I have 5000 miles the regen message to drive 20 miles came on this morning and I drove my normal weekly commute of 300 miles straight with no stops the message is still on as is the check engine light. I would guess something is broken and ideas.


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## Tomko (Jun 1, 2013)

knronald said:


> My car is now 1 month old and I have 5000 miles the regen message to drive 20 miles came on this morning and I drove my normal weekly commute of 300 miles straight with no stops the message is still on as is the check engine light. I would guess something is broken and ideas.


Press OnStar and ask them to run a diagnostic and take note of the code then visit your dealership for a warranty repair as necessary.


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## plasticplant (Mar 26, 2013)

knronald said:


> My car is now 1 month old and I have 5000 miles the regen message to drive 20 miles came on this morning and I drove my normal weekly commute of 300 miles straight with no stops the message is still on as is the check engine light. I would guess something is broken and ideas.


Yup. Certainly not right. Do as Tomko has instructed. I'm sure it's sensor related. A manual regen at the dealer may also be in order. Keep us updated.


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## Boog8302 (Sep 6, 2013)

Back in May (I think it was May could have been March), my car went through a regen. It went into limp mode and I had to take it into the dealership. While it was there they also did some other work...this was after I tried to go through high water but got stuck. Yea I know I should have stopped but When I hit my breaks I slid and would have hit another care if I didnt turn the way I did. Anyways, they did their regen and I have never had the issue again. I think I probably had around 20k miles at that point on the car. Anyways the care did the same thing where it would come up with the message and it wouldnt go away no matter how far I drove it. Dealership took care of me though.


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## diesel (Jun 8, 2013)

knronald said:


> My car is now 1 month old and I have 5000 miles the regen message to drive 20 miles came on this morning and I drove my normal weekly commute of 300 miles straight with no stops the message is still on as is the check engine light. I would guess something is broken and ideas.


Please let us know what the dealer finds out on this and what the resolution is. Nothing like this has happened to me in 82K miles. Good luck and keep us posted.


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## 72specialized (Apr 24, 2016)

I know I'm raising the dead here but I have a quick question regarding regens. How long is the average regen?


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## Snipesy (Dec 7, 2015)

72specialized said:


> I know I'm raising the dead here but I have a quick question regarding regens. How long is the average regen?


They shouldn't take more than 20 minutes, usually much quicker.


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## diesel (Jun 8, 2013)

72specialized said:


> I know I'm raising the dead here but I have a quick question regarding regens. How long is the average regen?


On the highway, I'd say about 1 gram every mile or less. 15ish minutes total, maybe less.


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## revjpeterson (Oct 2, 2013)

Since I got the bi-scan add on and PID set for the torque app, I've been able to watch my soot level more closely. If I'm on my way home, and I know I'm in a re-gen, I'll kick it down a gear or two to see if I can finish it off without driving extra or parking before it's done. Last night, I had 3 miles to home and was still at 11 grams. I dropped it to 4th gear going 55-60 mph (a little under 3000 rpm) and managed to burn off 6 grams of soot in 2.5 miles and finished the last 2 grams driving 25 mph in 2nd gear (about 2500 rpm) through my neighborhood to complete just in time to coast out the last block to the driveway and cool down the turbo. It smelled like a blacksmith's shop when I got out, and the fan was screaming, but it did burn off quickly. 

The point of all that is that it is possible to significantly speed up the re-gens using lower gears. A highway re-gen usually takes me about 4-6 bars on my mpg graph in the DIC (12-20 miles), but when I kick up the rpms, I can usually finish one off in 2-3 bars (about 6-10 miles)--so roughly half the time/miles.


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## 72specialized (Apr 24, 2016)

I've just noticed it lately "steaming" when I get my destination. It stinks so I'm guessing it was in a regen. I drive a ton (60000km) in a year so haven't had any issues. Would of been nice if GM put an option idiot light on the dash when it was doing a regen.


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## VtTD (Nov 5, 2013)

For better or worse, unless I'm on the highway, I can tell when it's in a regen because of the occasional to common surging at low RPMs. I do more city than highway driving now so I usually put it into manual to keep the RPMs up too. Sure right it smells, but it gets the job done fast!



revjpeterson said:


> Since I got the bi-scan add on and PID set for the torque app, I've been able to watch my soot level more closely. If I'm on my way home, and I know I'm in a re-gen, I'll kick it down a gear or two to see if I can finish it off without driving extra or parking before it's done. Last night, I had 3 miles to home and was still at 11 grams. I dropped it to 4th gear going 55-60 mph (a little under 3000 rpm) and managed to burn off 6 grams of soot in 2.5 miles and finished the last 2 grams driving 25 mph in 2nd gear (about 2500 rpm) through my neighborhood to complete just in time to coast out the last block to the driveway and cool down the turbo. It smelled like a blacksmith's shop when I got out, and the fan was screaming, but it did burn off quickly.
> 
> The point of all that is that it is possible to significantly speed up the re-gens using lower gears. A highway re-gen usually takes me about 4-6 bars on my mpg graph in the DIC (12-20 miles), but when I kick up the rpms, I can usually finish one off in 2-3 bars (about 6-10 miles)--so roughly half the time/miles.


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## Rivergoer (Mar 30, 2017)

revjpeterson said:


> Since I got the bi-scan add on and PID set for the torque app, I've been able to watch my soot level more closely. If I'm on my way home, and I know I'm in a re-gen, I'll kick it down a gear or two to see if I can finish it off without driving extra or parking before it's done. Last night, I had 3 miles to home and was still at 11 grams. I dropped it to 4th gear going 55-60 mph (a little under 3000 rpm) and managed to burn off 6 grams of soot in 2.5 miles and finished the last 2 grams driving 25 mph in 2nd gear (about 2500 rpm) through my neighborhood to complete just in time to coast out the last block to the driveway and cool down the turbo. It smelled like a blacksmith's shop when I got out, and the fan was screaming, but it did burn off quickly.
> 
> The point of all that is that it is possible to significantly speed up the re-gens using lower gears. A highway re-gen usually takes me about 4-6 bars on my mpg graph in the DIC (12-20 miles), but when I kick up the rpms, I can usually finish one off in 2-3 bars (about 6-10 miles)--so roughly half the time/miles.


Rev, in your experience can the ‘drop a gear’ technique possibly be used to trigger a Regen cycle when it is imminent? 

Today, per my Scangauge 2, Soot Mass went from 15 up to 20 grams in about 50 city miles. It had been 585 miles since last Regen so it was due for sure. 

To avoid interrupting the Regen cycle in city traffic, I jumped on the highway figuring regen would initiate fairly quickly. After driving nearly 80 miles @ 55 mph avg, Soot Mass was still at 20 grams and no Regen.

So I’m interested to learn if there’s any way to manually ‘trigger’ a pending regen (20 STM and 500+ miles since last regen) using driving techniques?

Also, my Scangauge cannot manually trigger a regen, is there another tool out there that can?


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## boraz (Aug 29, 2013)

Rivergoer said:


> Also, my Scangauge cannot manually trigger a regen, is there another tool out there that can?


 @Snipesy's app does

you need android


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## Rivergoer (Mar 30, 2017)

Dang...nothin for iPhone or iPad?


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## boraz (Aug 29, 2013)

Rivergoer said:


> Dang...nothin for iPhone or iPad?


nope


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## IndyDiesel (May 24, 2015)

I quit using the scanguage several months ago, it started flashing, it was sorta nice having it but I can’t say I miss it, I normally know when it is regening by just paying attention to my car, I really don’t miss it at all. I realize I may have to have a manual regen eventually and that’s ok. I figure since I drive mostly highway miles it may be less likely.


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## Snipesy (Dec 7, 2015)

There's 2 big issues with iOS.

1. It doesn't support bluetooth SPP. It does support BLE, but BLE is too slow with the adapter's control overhead.

2. It doesn't support background services. Which is really bad if you are doing a regen cause every time you leave the app all communications cease.



Something I've been toying with is using Android Things in a little box you just hook up to your obd2. That box would then do everything. What I am working on now is setup to work EXACTLY like this, it's just done internally on the phone.

Problem is I'm not a hardware guy. There is a lot of work that goes in before you can just release a piece of hardware... Moldings, certifications, QA, shipping, etc.


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## boraz (Aug 29, 2013)

Snipesy said:


> There's 2 big issues with iOS.
> 
> 1. It doesn't support bluetooth SPP. It does support BLE, but BLE is too slow with the adapter's control overhead.
> 
> ...


i see $50 android tablets all the time

any idea if theyd be good enough to run your app? or what requirements?


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## Snipesy (Dec 7, 2015)

boraz said:


> i see $50 android tablets all the time
> 
> any idea if theyd be good enough to run your app? or what requirements?



Pretty much anything these days will run BiScan and Torque.. At least computationally... Some phones throw a fit for other reasons.

The newer app I honestly can't say. I have done a lot of work with optimizing it though.


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