Is there a passive regen that takes place after the active if SL and RG are not at 0%

Yep. I see this every regen as well.

 

I don't know for sure but I think that the passive regen is passive. It kind of takes place in the background when ever the exhaust temp gets high enough to burn off the soot in the DPF. It's not something that is commanded on or off. Could be that when the regen stops, the exhaust system is still hot enough to continue to burn the soot off. (as far as I know).

 

Could be that when the regen stops, the exhaust system is still hot enough to continue to burn the soot off. (as far as I know).

This would be my guess. I had a regen recently where I took a stop after a lot of climbing so I know the exhaust was very warm. Soot was reading 54% when I stopped, and I spent about a half hour in the store. When I came back out and started up, regen restarted but the soot was down to 44%. Regen ultimately stopped before 840 miles (835-ish, IIRC).

Is there a passive regen that takes place after the active if SL and RG are not at 0%

Every time you heat up the exhaust "enough", there is a passive burn-off of soot. There's enough good hills around where I live that I know I'll lose a few % of soot going over them because I actually have to press down on the pedal.

 

Every time you heat up the exhaust "enough", there is a passive burn-off of soot.

Makes sense. I guess from an engineering perspective there's no reason to keep regen active until 0% when you know the exhaust will still be hot enough to burn off what remains.

 

If my regen is interrupted several times, it usually quits around 5-10%. Last week on a long highway stretch it regened down to 2% then kicked off, and % fell to 0 zero shortly after. By the time I got home it was back up to 35%. Truck sat all night, and after about 3 miles of driving the next morning , soot % fell to back to 15%.

Its annoying how much I watch these regens and there seems to be zero consistency on how fast soot builds. Id say my average regen is every 400 miles, seen as high as 500 and low as 300. Honestly, considering removing my Edge CTS, because I obsess over it and watch it constantly trying to make any sense of it lol. I have 10k on the truck now (2024 L5p) and have had zero keep driving messages. I do have 20 mile highway trip to work each way, so it has plenty of time to complete a regen within a days driving. Everything else is suburban/city driving.

 

Id say my average regen is every 400 miles, seen as high as 500 and low as 300

The 2024s shock me with their regen frequency. I get 840 finished regen to finished regen, pretty much on the dot. Every once in a while I'll do enough near-idle work that it will push the regen down into the low 700s, but that will take several hours of that type of work to modify a regen cycle for me.

there seems to be zero consistency on how fast soot builds

There isn't, and because of that I mostly ignore soot%. Regen% is a different measure (if your gauge has it). I mostly watch soot% for curiosity.

Today I did some hard hauling, which usually makes my soot% go down. Instead it went up. I blame the rain.

 

The 2024s shock me with their regen frequency. I get 840 finished regen to finished regen, pretty much on the dot. Every once in a while I'll do enough near-idle work that it will push the regen down into the low 700s, but that will take several hours of that type of work to modify a regen cycle for me.



There isn't, and because of that I mostly ignore soot%. Regen% is a different measure (if your gauge has it). I mostly watch soot% for curiosity.

Today I did some hard hauling, which usually makes my soot% go down. Instead it went up. I blame the rain.

What’s the difference between soot % and regen %? Mine seam to mirror each other . Do I have the right gauge selected ?

 

Regen % always drops the next morning with a cold/cool engine and you first starting driving. In the winter/cold temps the number drops quite a bit (usually 20%), in the summer not as much (usually 10% max). Longer distances between regens in the winter. Summer my LM2 gets usually 320-340 miles for the type of driving I do, winter there are a lot of times it’s up in the 450 mile range (same routine).

 

Regen % is what triggers the regen cycle to start. Once it gets to 100% and stays there for a little bit that’s when the regen starts.

 

This has been discussed many times, the 6.6L L5P HD regens every 800 miles but the 3.0L LM2/LZ0 don’t. These smaller baby Dmax regen based on the DPF regen % on the iDash once it hits 100%. It won’t be any near 800 miles, be lucky to get 1/2 that distance. Longer regen distances in the winter with the colder temps, shorter in the summer with the heat.

 

but the 3.0L LM2/LZ0 don’t. These smaller baby Dmax regen based on the DPF regen % on the iDash once it hits 100%. It won’t be any near 800 miles, be lucky to get 1/2 that distance

My LZ0 consistently kicked off regens at 621/622 miles with soot load far below 100% (a couple times at 40% SL) during the coldest parts of winter. Definitely shorter in the summer where it is down to 150-200 right now.

 

At 620 miles, you are doing VERY well then. You see what I mean then when I say the summer regen distance is shorter. I said DPF regen % and not soot % level, it will regen before soot level gets to 100% as there are other factors in the 3.0 regen. But if you monitor that one I said, you will know when the regen is going to happen.

 

Can someone explain which temps are best to monitor on the iDash for regen? My understanding is that that EGT 1 thru 3 are temps before/at/after the DPF. If choosing one, which is best or most appropriate to monitor? Also, when monitoring overall exhaust temps to avoid damage to the engine, is EGR temp (pre-turbo) the best? Wanted to set an alert limit... 1300 ⁰F appropriate? Learning as I go. Thanks!

 

is EGR temp (pre-turbo) the best?

That's the one I watch. I won't say for sure it's the "right" one to watch.

As a side note, I disconnected a trailer over the weekend during a regen. Holy F#%@$@# that exhaust was hot!

 

After finding another post by chaseydog on another thread, I now know where the EGT sensors are. The recommendation from Demonworks is monitoring EGT1. Still have the same question about which PID parameter alert (and temp upper limit) would be best to prevent damage to the LZO engine.

 

Is your truck modified or stock fuelling?

 

My LZ0 regens anywhere between 275 and 800 miles. Not sure why it varies so much, but it does.

 

I've never had mine go over 400

 

During the cold in the winter, I see 622 with less than 50% soot load often. Not sure how anyone would get more than 622 between regens.

 

Looks like the LZO has a lower 'max miles' limit that the L5P

 

Yep, I hit the 806/807 in my l5p all the time.

 

Do your LZO and L5P pull trailers / do jobs that makes them work harder than daily driver duty?

I