[firehawk618]

I found this interesting. With the Scangauge and Xgauge for "DPF Soot load %" setup and displayed at all times so far for the last 5 days I have noticed my soot load started at 49%. With highway driving and gradual acceleration off the line when taking off I have only seen it go up to 51% and that took 2 days.

Doing some full throttle runs from a stop deliberately trying to add soot I noticed it wasn't too difficult to make that load climb. I had it as high as 57% at one point.

I am doing all this to learn the behavior of the system. Here's where it gets odd to me.

I had the load to around 57% and quit fooling around with it. I figured the quick climb in load was due to me inducing soot into the system by my driving which I expected.

When on the freeway I mashed the pedal when I was already going 70mph. Held it down to get to 90 so basically ran it to the redline.

When I was done and coasted back down I noticed the soot load had gone down to 51%!

ROFL I never imagined the ol' Italian tune up would actually blow soot out of the DPF.

After the trip I am back home and it's at 50% again.

I have almost 700 miles since my last regen and am watching regen status with the Scangauge. So far since I installed the gauge I have not had a regen.

I verified DPF soot load with my Solus and GDS2 and it appears accurate.

 

[firehawk618]

I want to do a forced regen to see what the soot load sits at after a fresh cleaning yet part of me wants to ride it out and let the car do a regen when it sees fit and at what percentage of soot load it takes to initiate a regen.

My car has around 2400 miles. It's had 2 regens logged and they averaged 8xx miles between regens according to the PCM.

If the 8xx mile thing continues then it's due for another regen soon however if it uses soot load as one of the parameters when deciding when to do a regen then I doubt I'll see one anytime soon.

 

[firehawk618]

This shot was several days ago. Notice the *DIS* is 238. That's distance since regen. It's around 7xx now and the soot load is lower than displayed in the image.

 

[Diesel4Ever]

This shot was several days ago. Notice the *DIS* is 238. That's distance since regen. It's around 7xx now and the soot load is lower than displayed in the image.

It’s doing a passive regen while you’re driven on the freeway. There is enough heat in the exhaust to burn some soot while at speed.

The 800 mile interval may be triggered as a default value, regardless of the % status of actual soot load.

 

[firehawk618]

From what I understand so far a passive regen doesn't inject diesel in the exhaust stroke and an active one does.

800 is a rough number. It's just the average mileage between my 2 regens that are logged in the PCM. I am doubting there's a hard number it uses to do an active regen whether it needs it or not but would like to see information supporting either argument.

 

[firehawk618]

I'll wait for my soot load to increase to around 60 if it ever gets that high and do another Italian tune up on the freeway to see if it behaves the same way again.

 

[LiveTrash]

Even though your gauge may be accurate, keep in mind the sensor is an estimate, not an exact value. Small increments should be taken lightly. However, as mentioned, the decrease in soot is due to the heat buildup from the highway driving. I have never observed this in my Gen 1, but it does it all the time in my work truck. I can only imagine the system in the Gen 2 Cruze is more efficient with the regenerations.

 

[Diesel4Ever]

From what I understand so far a passive regen doesn't inject diesel in the exhaust stroke and an active one does.

800 is a rough number. It's just the average mileage between my 2 regens that are logged in the PCM. I am doubting there's a hard number it uses to do an active regen whether it needs it or not but would like to see information supporting either argument.

It measures soot load by delta P across the filter.

Some diesels with DPF have a default mileage trigger for regeneration. My TDI does, about every 500 miles. I think it’s a common strategy for keeping the filter clean.

 

[firehawk618]

It measures soot load by delta P across the filter.

Some diesels with DPF have a default mileage trigger for regeneration. My TDI does, about every 500 miles. I think it’s a common strategy for keeping the filter clean.

Yes. I haven't looked yet but I would imagine there's a DPF pressure sensor at each end of the filter.

I will keep an eye on things and see over time what the logic GM is using on the system.

 

[firehawk618]

On a related note. I have to imagine that the auto stop / start is **** on the DPF and EGR of the diesels.

The transit agency I work at has a specific fleet that does have the auto start / stop + cummins ISB and they're nothing but after treatment + egr headaches.

 

[firehawk618]

I'm at a 800 miles and no active regen. Calculated soot load still sits around 50%. Will climb to 54% and dip to 49% but 50% seems to be it's target.

I'm going to force a regen this evening to see what calculated load it will end up at when done for my information.

 

[firehawk618]

Well I was sitting at 50% soot load for as long as I have been monitoring it. Curiosity got the best of me so I forced a regen.

To my surprise it seem to zero calculated soot load after the regen.

Pics when I get home

 

[froyofanatic]

Can I see soot load with a OBD2 sensor and an app like Torque?

 

[firehawk618]

Can I see soot load with a OBD2 sensor and an app like Torque?

Maybe if you can find and program the PIDs into torque.

I don't use Torque. I want my phone screen clear for other apps, my obdii port is occupied with the Scangauge and I don't want another device on my dashboard.

 

[Cruz15]

My reader says 0 regens so far, I am at 3100 kms so I doubt its accurate. I have seen the car throw extra fuel in the engine alot more often than the 2015 I had.
So far I am getting worse mileage than my 2015. The engine just cant seem dip down into the 2 - 3 l/100 km like my 2015 did.

 

[firehawk618]

My reader says 0 regens so far, I am at 3100 kms so I doubt its accurate. I have seen the car throw extra fuel in the engine alot more often than the 2015 I had.
So far I am getting worse mileage than my 2015. The engine just cant seem dip down into the 2 - 3 l/100 km like my 2015 did.

What reader are you using?

I have used GDS2 and a high end Snap on tool that is updated to current levels to read mine.

The Scangauge also reads the same as both the tools above.

 

[Diesel4Ever]

Regen Pro-Tips:

If it's cold outside and you’re in the middle of a Regen and about to shut off the car, don't do it. As the exhaust cools down over night the water vapor inside the exhaust will condense in the soot left in the DPF and form a wet "muck" sludge that will take much longer to finally burn off when you re-start the car. It's best to do the following before the car is parked.

If you notice that you’re in the middle of a Regen, and you plan on parking soon. Or just want to get if over with quick:

Put it in a higher gear 4-6 if a MT, 6-9 in manual mode if the AT, depending on speed limit. Accelerate hard (50-75%+ throttle) up to 4K and then engine brake down to 2k. Repeat. Make sure your coasting down under load after accelerating. Do this 4-5 times and your regen will be done. With all this extra heat and pressure being placed on the DPF it takes like 5 min or less to be completed. A hypermiler told me about it and it works.

 

[Barry Allen]

So, some questions:

Exactly what do these cars do during a forced regeneration? If it's done while parked, why can't this be done by users instead of having to take it to a dealership and have their plug-in computer trigger it?

 

[IndyDiesel]

Regen Pro-Tips:

If it's cold outside and you’re in the middle of a Regen and about to shut off the car, don't do it. As the exhaust cools down over night the water vapor inside the exhaust will condense in the soot left in the DPF and form a wet "muck" sludge that will take much longer to finally burn off when you re-start the car. It's best to do the following before the car is parked.

If you notice that you’re in the middle of a Regen, and you plan on parking soon. Or just want to get if over with quick:

Put it in a higher gear 4-6 if a MT, 6-9 in manual mode if the AT, depending on speed limit. Accelerate hard (50-75%+ throttle) up to 4K and then engine brake down to 2k. Repeat. Make sure your coasting down under load after accelerating. Do this 4-5 times and your regen will be done. With all this extra heat and pressure being placed on the DPF it takes like 5 min or less to be completed. A hypermiler told me about it and it works.

What you are suggesting does work, I have done it once or twice, but perhaps if it’s an option just keep driving for a few more minutes which is less stress on the car for sure.

 

[Rivergoer]

So, some questions:

Exactly what do these cars do during a forced regeneration? If it's done while parked, why can't this be done by users instead of having to take it to a dealership and have their plug-in computer trigger it?

After several failed/incomplete regen attempts, a code sets, car goes to limp mode and cannot be cleared until the dealer plugs in and forces a regen. Something to do with the GM proprietary software...maybe @Robby can expound further.

Whether users with @Snipesy ‘s Android app can manually command a forced regen under those circumstances, I’m not sure.