24 Hour Regens No Longer Happen

[Will_T]

The one on the EVIC is the one that takes time into the reading, not the one on an iDash or Edge CTS.

Jay

If that is the case, why does my EVIC say zero but the iDash PID is at 96%? I am confused and certainly not understanding all this for sure.

 

[John Jensen]

Also I have seen it said in other threads that a regen will be triggered long before your true soot load gets to 100%. Not sure if that is correct but it makes sense.

Makes sense. Regardless of the % soot, when the 23-24 hour time comes up it will regen

 

[Jay P]

If that is the case, why does my EVIC say zero but the iDash PID is at 96%? I am confused and certainly not understanding all this for sure.

The one on the dash is more of an indication of how much soot you are adding (driving style) or soot load over time. I would ignore the one on the EVIC and use the one your idash.
There is a whole thread going on the dash one. There is some good reading there but I wouldn't worry about that until you figure out your regen issue.

Jay

 

[Will_T]

At this piont a manual regen may help. If you don't see diff press change I would suspect an issue with the diff pressure sensor.

Jay

When you say a manual regen do you mean taking it to the dealer? Or can you make one happen yourself? If our dealer here would even agree to do it, I am sure the wait for an appointment would be several months like it is for anything at that dealer. (Their service dept is still 50% staffed at best.)

At this point I don't think I need to do that. I have seen nothing that indicates that there is a real problem yet except for maybe it not doing the 24 hr regens for the last couple of cycles. But as mentioned there could be reasons for that time being off if the dealer has possibly updated the software the last couple of time I was in. I noticed again when I had the oil changed a few weeks ago, when I got the truck back, some of my EVIC customizations were back to default. I went in and asked if they had flashed new software and the service writer said there was nothing on the invoice but the tech may have done it just as a matter of course. He did not think so and the tech had left for lunch so I just dropped it. I will try to locate and display that diff pressure PID you described and see what that does. Also, I will be watching that top right PID display to see what happens when it gets to 100%. Hopefully the DPFDP1 PID will behave as you described and the truck will regen when the other PID gets to 100% or before. I am hoping that there is a logical explanation, (like computer flashes or me just missing them), that will explain why I have not seen a regen since 120 hours. If the counting of the 24 hours has just been thrown off by something, and because of my driving style the soot load is low, then that would explain why one or two 24 hour regens appear to have been skipped.

 

[AH64ID]

No longer regening on the 24 hour mark remains a mystery.

I don't think my % soot level PID is the same as what you are monitoring. Mine has nothing to do with time, it is formulated from the DPF pressure sensors. And without fail, when it reaches 100% a regen takes place. It also regens every 23-24 hours engine time.

I am pretty sure you are monitoring the same PID I am with the CTS3. Time is absolutely a factor. Unless the DPF gauge is around 50% the PID will get to 100% at 24 run time hours.

When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. while driving you can watch it gain 1% every 14.4 minutes.

Below ~45% the percentage jumps up and down with DPF loading, but above that time is the only driving factor. That’s with a driving style that keeps the DPF gauge at 0% and gets to 24 hours every time.

 

[Will_T]

I am pretty sure you are monitoring the same PID I am with the CTS3. Time is absolutely a factor.

When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. while driving you can watch it gain 1% every

I like this and it is something I have not paid attention to. If you are correct, then my current 96% would mean the truck thinks it has been 23 hours since the last regen and will do another in two one hour. Now I will just have to wait and see.

If it does happen like that and I get a regen in two hours at 171 engine hours, that will have been 51 hours since my last regen at 120 hours. So that would be a pretty good indication that something like a computer flash reset or messed up the 24 hour timer.

 

[AH64ID]

The one on the dash is more of an indication of how much soot you are adding (driving style) or soot load over time. I would ignore the one on the EVIC and use the one your idash.
There is a whole thread going on the dash one. There is some good reading there but I wouldn't worry about that until you figure out your regen issue.

Jay

There isn’t a PID for just DPF soot loading, the PID is for %age towards an active regen. That’s where the dash is nice, because it just shows you soot loading. 0% is a good thing, but you don’t know that the DPF is at 0% just with the PID.

 

[AH64ID]

I like this and it is something I have not paid attention to. If you are correct, then my current 96% would mean the truck thinks it has been 23 hours since the last regen and will do another in two hours. Now I will just have to wait and see.

You have less than 1 hour of run time until a regen. 96% of 14 hours is 23 hours and 2 minutes since last completion.

 

[Will_T]

You have less than 1 hour of run time until a regen. 96% of 14 hours is 23 hours and 2 minutes since last completion.

Yes, thanks. I messed up my train of thought on that previous post when I said the truck thinks it is at 23 hours so it will be 2 hours until the next regen! Makes me want to just go out on an unecessary one hour drive just to get it over with and know.

 

[Will_T]

Anyone know what this "diagnostic" PID shows? It is not the ON/OFF PID, that is another one.

Emissions

Diagnostics

REGEN

Dpf Regen Status

Or this one?

Emissions

Diagnostics

PMF M

Monitor - PM Filter

 

[Jay P]

There isn’t a PID for just DPF soot loading, the PID is for %age towards an active regen. That’s where the dash is nice, because it just shows you soot loading. 0% is a good thing, but you don’t know that the DPF is at 0% just with the PID.

While you are correct, 100% is the soot loading value (based on differential pressure) where the engineers decided that an active regen should take place. The DPF will hold a lot more soot than what triggers a regen but it will cost power due to increased pressure across the DPF.
On an odd note both GM & Ford have a PID for soot loading in grams but just like the percentage RAM uses it's a calculated PID based on differential pressure and some other monitored values.

Jay

 

[John Jensen]

There isn’t a PID for just DPF soot loading, the PID is for %age towards an active regen. That’s where the dash is nice, because it just shows you soot loading. 0% is a good thing, but you don’t know that the DPF is at 0% just with the PID.

I disagree. Once when I was only doing short trip local driving my CTS3 went to 100% and regened at about 15 hour point since the last regen. I believe the PID % soot is a reading of DPF pressures and is not age-related. When it doesn't regen until the 24 hour period, yes, it reads like you say, "When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. ". Thoughts?

 

[Will_T]

I disagree. Once when I was only doing short trip local driving my CTS3 went to 100% and regened at about 15 hour point since the last regen. I believe the PID % soot is a reading of DPF pressures and is not age-related. When it doesn't regen until the 24 hour period, yes, it reads like you say, "When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. ". Thoughts?

This is getting crazy hard to keep straight! How would you correlate that to posts #s 46 and 48?

I was just getting to the point where I thought my soot level probably really is close to or at zero, but a regen will happen anyway in less than an hour of engine time.

 

[John Jensen]

This is getting crazy hard to keep straight! How would you correlate that to posts #s 46 and 48?

I was just getting to the point where I thought my soot level probably really is close to or at zero, but a regen will happen anyway in less than an hour of engine time.

Correlates exactly. I said, When it doesn't regen until the 24 hour period, yes, it reads like you say, "When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. ". You haven't regened mid 24 hours

 

[AH64ID]

While you are correct, 100% is the soot loading value (based on differential pressure) where the engineers decided that an active regen should take place. The DPF will hold a lot more soot than what triggers a regen but it will cost power due to increased pressure across the DPF.
On an odd note both GM & Ford have a PID for soot loading in grams but just like the percentage RAM uses it's a calculated PID based on differential pressure and some other monitored values.

Jay

100% soot loading is where you get a power derate, an active regen is triggered much sooner (~45-50%) and you start getting warnings at 70 or 80% (can’t recall which).

I disagree. Once when I was only doing short trip local driving my CTS3 went to 100% and regened at about 15 hour point since the last regen. I believe the PID % soot is a reading of DPF pressures and is not age-related. When it doesn't regen until the 24 hour period, yes, it reads like you say, "When you are 12 hours since a regen it will be at 50%, 18 hours 75%, etc. ". Thoughts?

Yes, that goes inline with what I was saying. Basically it’s whatever will trigger the regen first, time or soot loading. A regen happens at 100%.

With the dash gauge staying at 0% you will regen based on time, which means time since last regen can be calculated by the percentage once you get above 45% (in my experience).

 

[AH64ID]

I was just getting to the point where I thought my soot level probably really is close to or at zero, but a regen will happen anyway in less than an hour of engine time.

This looks correct to me, based on what you have posted and I have witnessed.

 

[Jay P]

I will add a little more confusion... When DPF temps reach 600 to 700 the DPF will do passive regen (usually towing or going up a hill) which will bring down the percentage shown on your iDash.

 

[Jay P]

100% soot loading is where you get a power derate, an active regen is triggered much sooner (~45-50%) and you start getting warnings at 70 or 80% (can’t recall which).

That's the same thing I said, maybe I wasn't clear where I put 100% but I meant your CTS or iDash shows 100%.

 

[Will_T]

You haven't regened mid 24 hours

And if a regen happens mid 24 hours, that would reset the 24 hours, correct?

 

[John Jensen]

I will add a little more confusion... When DPF temps reach 600 to 700 the DPF will do passive regen (usually towing or going up a hill) which will bring down the percentage shown on your iDash.

Yes. I have seen that happen on my CTS3 on my trips to Oregon. I believe the passive regenning is what allows the truck to go to the 23-24 hour mark for an active regen. It's when the truck is driven locally or for short trips that it will regen sooner as it loads the DPF faster, and no passive regens occur because it doesn't reach the required temps,