Regen?

[cycling4life]

On my 21, it's also only on the DPF screen. I just happen to be flipping the screens while I was driving and saw a regen in progress. Do you guys always go to this screen before shutting off the engine. I was just wondering if I had not seen the message and parked the car would I have any issues interrupting the regen process?

 

[Darmichar]

On my 21, it's also only on the DPF screen. I just happen to be flipping the screens while I was driving and saw a regen in progress. Do you guys always go to this screen before shutting off the engine. I was just wondering if I had not seen the message and parked the car would I have any issues interrupting the regen process?

If you do shut the truck off while it is in regen, it will start it again the next time the truck is started.

 

[Will_T]

The %soot changes according to your driving conditions, it's not a lineal progression, time has nothing to do with it, solely measuring DPF pressures which are converted to %soot. When it reaches 100% it will regen, and I think you'll find that you'll be close to the 24 hour mark

Yes but Banks says that the "Regen Trigger" is not measuring soot%. But I now think it might be. Also given that the Regen Trigger PID is now showing 32% and it has only been 1 hour since the last regen. I will report back after the next time I tow my TT.

What I think will happen and has been happening, and what I probably would have seen if I had been displaying this Regen Trigger gauge on my iDash is this.... The % might be at some higher % like it is now at 32% after just an hour or two since the last regen. But then I tow my TT and that does a "passive" regen that lowers the Regen Trigger % to some lower number like 7%. Then the next time I drive in town a little it climbs back up. But because I mostly tow with the truck, those passive regens keep lowing the % so it never gets to 80, 90, 100% or whatever would trigger a regen. So on my truck, with mostly towing miles, the only regens that have happened so far are those that are triggered by the engine hour clock hitting a 24 hour mark. Like I said, it has not been approximate. My regens have occurred exactly at 24, 48, 72, 96, and 120 engine hours.

 

[John Jensen]

Yes but Banks says that the "Regen Trigger" is not measuring soot%. But I now think it might be. Also given that the Regen Trigger PID is now showing 32% and it has only been 1 hour since the last regen. I will report back after the next time I tow my TT.

What I think will happen and has been happening, and what I probably would have seen if I had been displaying this Regen Trigger gauge on my iDash is this.... The % might be at some higher % like it is now at 32% after just an hour or two since the last regen. But then I tow my TT and that does a "passive" regen that lowers the Regen Trigger % to some lower number like 7%. Then the next time I drive in town a little it climbs back up. But because I mostly tow with the truck, those passive regens keep lowing the % so it never gets to 80, 90, 100% or whatever would trigger a regen. So on my truck, with mostly towing miles, the only regens that have happened so far are those that are triggered by the engine hour clock hitting a 24 hour mark. Like I said, it has not been approximate. My regens have occurred exactly at 24, 48, 72, 96, and 120 engine hours.

Not sure how the Banks' PID works. The Edge PID returns to 9% after a regen. I don't think it can go below 9% as they use that number for "residual soot" still in the DPF.

Edited:
I just had a regen at 100% soot and 173 hours.
The truck will regen anytime it hits 100%. I'm thinking 100% and 24 hours are synonymous, just different trigger names. It may regen in 24-25 hour increments regardless of % soot, but I don't think so.
Will test that theory when make my annual 2000 mile trip in September.

 

[Will_T]

I just had a regen at 100% soot and 173 hours.
The truck will regen anytime it hits 100%. I'm thinking 100% and 24 hours are synonymous

I don't think so since your 173 hours is not a multiplier of 24. The closest to that would be at 168 hours. If my regens continue like they have been, I expect I will have regens coming up at exactly 144, 168, and 192 hours.

Edit: Maybe 100% or 24 hours whichever happens first? And then, because of my driving habits, 24 hours is always first for me.

I will see at 144 hours when I have a regen, what my Trigger % is. And I will watch that trigger % as I tow to see if it goes down.

 

[superjoe83]

I monitored my regens when I had my 4th gen, and used the trigger% as my main indication of when a regen would happen. I believe the % is referenced to time more than anything else, mine would regen at 1520min religiously, didn't matter how I drove it. The % would never go down even if I was pulling my 18k toy hauler over mountain ranges with 1000 degree exhaust temps for minutes at a time, also right after the regen the % would be around 25% then after a shutdown and restart it would go down close to 0% but quickly come back up to around 15-20% and then slowly count back up to 100%

 

[Darmichar]

I monitored my regens when I had my 4th gen, and used the trigger% as my main indication of when a regen would happen. I believe the % is referenced to time more than anything else, mine would regen at 1520min religiously, didn't matter how I drove it. The % would never go down even if I was pulling my 18k toy hauler over mountain ranges with 1000 degree exhaust temps for minutes at a time, also right after the regen the % would be around 25% then after a shutdown and restart it would go down close to 0% but quickly come back up to around 15-20% and then slowly count back up to 100%

There could also be a debounce timer on those readings in the ECM to allow those readings to normalize once the truck warms up.

 

[John Jensen]

I monitored my regens when I had my 4th gen, and used the trigger% as my main indication of when a regen would happen. I believe the % is referenced to time more than anything else, mine would regen at 1520min religiously, didn't matter how I drove it. The % would never go down even if I was pulling my 18k toy hauler over mountain ranges with 1000 degree exhaust temps for minutes at a time, also right after the regen the % would be around 25% then after a shutdown and restart it would go down close to 0% but quickly come back up to around 15-20% and then slowly count back up to 100%

What were you monitoring with?

 

[Will_T]

I believe the % is referenced to time more than anything else

I originally thought that too but now am thinking not. Mainly because I am at hour one of a 24-hour clock/timer to my next regen and the Regen Trigger percentage is at 32%. Hour one of 24 would translate to 4.5% if the Regen Trigger was tracking time. After my next trip towing I will know more, and after my next regen should know for sure. But it could be a several months before I get another 23 hours on the engine.

 

[superjoe83]

What were you monitoring with?

The obdlink app that came with my obdlink mx interface

I had it set up like this

 

[John Jensen]

The obdlink app that came with my obdlink mx interface

I had it set up like this
View attachment 35299

Thanks. I've not tried that with my MX. Sensor 2 is recording the regen temps. Here's a good diagram

 

[Will_T]

I just had a regen at 100% soot and 173 hours.
The truck will regen anytime it hits 100%. I'm thinking 100% and 24 hours are synonymous, just different trigger names. It may regen in 24-25 hour increments regardless of % soot, but I don't think so.
Will test that theory when make my annual 2000 mile trip in September.

I originally thought that too but now am thinking not. Mainly because I am at hour one of a 24-hour clock/timer to my next regen and the Regen Trigger percentage is at 32%. Hour one of 24 would translate to 4.5% if the Regen Trigger was tracking time. After my next trip towing I will know more, and after my next regen should know for sure. But it could be a several months before I get another 23 hours on the engine.

I really can't make a lot of sense of this. As I posted, the last time I drove the truck I was at 1 hour on the engine time since last regen. In other words, for my truck, 23 hours to go until the next regen. Also as I posted, when I put up the Regen Trigger % on the iDash, at that time it was at 31% and after a bit of idling went to 32%. However, today I started the truck and hooked up a trailer. I just happened to look at the iDash Regn Trigger field and it is now at 3%. I wonder why and how it went from 32% when I shut off the truck a couple days ago to 3% today when I started it??? The 3% does make more sense than the 32% though if you think about 23 hours on the engine to go until the next regen. Or you think about it compared to the evic gauge which shows zero or maybe 2 or 3%. I will continue to watch the Regen Trigger field as I drive the truck and report back on what happens.

 

[Will_T]

OK. I am not sure at all what the Regen Trigger % is looking at. It is all over the place with readings. I just got back from a short camping trip towing the TT. The reading was 3% when I started the truck and then went to 4% as it was idling before I pulled out. Once I got under way, after a mile or maybe less, it was at 41%. It stayed between 40 and 45% for the 1 hour tow to the campground, Normal two lane highway driving, 45 to 60 mph. The last few miles is a pretty good uphill and I went at it fairly aggressively to see if that would make any difference and it did not. It was at 41% when reaching the campground. After unhooking, the truck sat for two days. When I started up this morning to hook back up, thr trigger reading was 4%. Once under way it jumped up to 35% and stayed up and down between 28 and 36% all the way home.

Can anyone make any sense of this behavior? I am not sure what the Regen Trigger % could be monitoring if it is not soot in the DPF or the % of time left until the next 24 hour regen.

 

[Ostracize]

OK. I am not sure at all what the Regen Trigger % is looking at. It is all over the place with readings. I just got back from a short camping trip towing the TT. The reading was 3% when I started the truck and then went to 4% as it was idling before I pulled out. Once I got under way, after a mile or maybe less, it was at 41%. It stayed between 40 and 45% for the 1 hour tow to the campground, Normal two lane highway driving, 45 to 60 mph. The last few miles is a pretty good uphill and I went at it fairly aggressively to see if that would make any difference and it did not. It was at 41% when reaching the campground. After unhooking, the truck sat for two days. When I started up this morning to hook back up, thr trigger reading was 4%. Once under way it jumped up to 35% and stayed up and down between 28 and 36% all the way home.

Can anyone make any sense of this behavior? I am not sure what the Regen Trigger % could be monitoring if it is not soot in the DPF or the % of time left until the next 24 hour regen.

It seems like, to me at least, your "regen trigger" is pulling data from the DPF's differential pressure sensor(s), which DPF soot level is derived from.
The exhaust has to be up to temp for accuracy and thus cold start % you are seeing will not be accurate.
The lack of change to 41% after your aggressiveness is likely the result of the passive regen doing its job in the short term... Towing creates higher average EGTs which allows for more efficient passive regen.

Sensor systems(like DP sensors) that were never meant for operator monitoring aren't designed to have the granularity (poll rate) to avoid operator confusion.
The cummins DPF system was seemingly designed to be "hands off"... Just keep the DEF filled and drive...