Regen warnings on RAM?

[waveslayer]

I must drive my truck like I stole it. No Regens yet with 5,000 miles or so

My wife thinks I only have 3 guns

 

[Will_T]

Well this is interesting. After explaining several times that my truck regens only on the 24-hour mark only things have changed. The first 7 regens were all exactly on 24 engine hour times. Now this time I am at about 29 hours and no regen yet. Driving has not changed. Almost all run time is towing the TT. I know I did not miss it because not only do I monitor and display EGTs, but my iDash has a big "Regen On/Off" display field. My DPF filter screen has been all over the place lately. For the first year+ it never left zero. Then it would sometimes be at close to 40 or 50%. Then the next time I drove the truck, back to zero. Not really logical how it could be close to 50% when the truck is shut off one day and then when started up a week later after just sitting, the gauge reads 0%.

 

[Darmichar]

Here's what I believe is happening.
The truck will regen if the soot level hits 80% before 25 hours have passed, and always every 25 hours.
An 80% regen will always take the 20 minutes or 20 miles
If there is no 80% regen it will regen at 25 hours and take whatever time or miles according to the soot level at that time.
If there is an 80% regen let's say at 20 hours, it will also regen at 25 hours regardless of soot level and may only take the 5 or 6 minutes as mentioned.
I could be totally wrong, but all that I have read and what's being reported makes me think the above.

This is the logic the Cat machines I work on follow. 80% is the regen trigger, usually measured by the differential pressure sensor. There are also time based triggers that vary based on the engine size and machine it is in (expected usage).

 

[H3LZSN1P3R]

Well this is interesting. After explaining several times that my truck regens only on the 24-hour mark only things have changed. The first 7 regens were all exactly on 24 engine hour times. Now this time I am at about 29 hours and no regen yet. Driving has not changed. Almost all run time is towing the TT. I know I did not miss it because not only do I monitor and display EGTs, but my iDash has a big "Regen On/Off" display field. My DPF filter screen has been all over the place lately. For the first year+ it never left zero. Then it would sometimes be at close to 40 or 50%. Then the next time I drove the truck, back to zero. Not really logical how it could be close to 50% when the truck is shut off one day and then when started up a week later after just sitting, the gauge reads 0%.

If it did passive regen while towing even your monitor would not pick it up

 

[Will_T]

If it did passive regen while towing even your monitor would not pick it up

I am curious about this "passive regen" that keeps being mentioned. Is it really a thing?

Or is it just a loose term for when you work the engine towing at speed and for a time and the EGTs get hot enough to burn off the soot? If it is the first, then you would think there would be a record of it in the computer that the iDash or similar could pick up. If it is just a colloquial term for "hot exhaust" then no, I guess there would be no way to know when it is happening? Unless there is an approximate temp that it occurs at in which case, I could see it, since I display 3 different EGTs on the iDash.

Maybe someone can explain? In any case, it should not matter in my case as for the first 7 regens I had on 24 hour marks, I was towing the same or harder as this last time where it has gone on by the 24-hour mark without a regen. What I am saying is that I am sure my exhaust was just as hot during those seven 24-hour regens as it has been lately. Maybe even hotter during the 24-hour regens time frame as those were long trips in mountains and hot desert. This time when it skipped the 24-hour regen, I have been around home with easy, short, cooler weather tows.

 

[flan]

Mine went off schedule by +7 a while back, I figured I’d had just missed the message like you. It then kicked in at the 31hr mark, and since then it’s been back to 24hr intervals. My next regen is due at 487hrs, which is not a multiplier of 24.

 

[Will_T]

Mine went off schedule by +7 a while back, I figured I’d had just missed the message like you. It then kicked in at the 31hr mark, and since then it’s been back to 24hr intervals. My next regen is due at 487hrs, which is not a multiplier of 24.

Interesting, I will see what hour my next "real" regen occurs at. I know for sure I did not miss the message but hopefully someone will explain this "passive regen" and whether it is a real event or as I said above, just a general term to say, "you must have had hot exhaust".

 

[Darmichar]

I am curious about this "passive regen" that keeps being mentioned. Is it really a thing?

Or is it just a loose term for when you work the engine towing at speed and for a time and the EGTs get hot enough to burn off the soot? If it is the first, then you would think there would be a record of it in the computer that the iDash or similar could pick up. If it is just a colloquial term for "hot exhaust" then no, I guess there would be no way to know when it is happening? Unless there is an approximate temp that it occurs at in which case, I could see it, since I display 3 different EGTs on the iDash.

Maybe someone can explain? In any case, it should not matter in my case as for the first 7 regens I had on 24 hour marks, I was towing the same or harder as this last time where it has gone on by the 24-hour mark without a regen. What I am saying is that I am sure my exhaust was just as hot during those seven 24-hour regens as it has been lately. Maybe even hotter during the 24-hour regens time frame as those were long trips in mountains and hot desert. This time when it skipped the 24-hour regen, I have been around home with easy, short, cooler weather tows.

Passive regen is a thing. If the exhaust is able to generate enough heat (Usually north of 700°F at the DPF) that is enough to 'regen' the system and burn off the soot, turning it to ash.

 

[Will_T]

Passive regen is a thing. If the exhaust is able to generate enough heat (Usually north of 700°F at the DPF) that is enough to 'regen' the system and burn off the soot, turning it to ash.

But apparently not enough of a thing for the truck's computer to pick it up. So, you just need to go on faith that it is happening and hope that you do not get the dreaded message that puts you in limp mode and tells you to see the dealer. I wish mine had just stayed on the 24-hour schedule so at least I would have assurance it was happening.

 

[Darmichar]

But apparently not enough of a thing for the truck's computer to pick it up so you just need to go on faith that it is happening?

I'm sure it probably could, but it's easier to measure backpressure with the DPF differential pressure sensor and gauge soot load that way.
Passive regens are just a benefit of working the engine hard.

 

[Will_T]

Passive regens are just a benefit of working the engine hard.

Thanks! I agree. But I just wish there was a way to know for sure that it has occurred. I suppose if the DPF screen on the evic was reliable that would help. But as stated by me and some others, ours is all over the place. Mine can be showing almost 1/2 full when I shut off the truck. Then upon restart for a short trip to the landfill, it will show zero% and stay there for weeks before briefly going up again. What's up with that? I don't think these trucks and do a passive regen when shut off.

 

[Darmichar]

Thanks! I agree. But I just wish there was a way to know for sure that it has occurred. I suppose if the DPF screen on the evic was reliable that would help. But as stated by me and some others, ours is all over the place. Mine can be showing almost 1/2 full when I shut off the truck. Then upon restart for a short trip to the landfill, it will show zero% and stay there for weeks before briefly going up again. What's up with that? I don't think these trucks and do a passive regen when shut off.

I completely agree there. I think it's a software issue in the DIC not truly showing the DPF soot load percentage accurately.
In 10 months of ownership mine has never came off of 0%. I find that really hard to believe as I seldom (currently) tow anything for long periods of time with mine.

 

[Will_T]

In 10 months of ownership mine has never came off of 0%. I find that really hard to believe as I seldom (currently) tow anything for long periods of time with mine.

Mine was the same for about the first year. Now it does the jumping up and down from zero to 40%+.

 

[Xflight29]

I just drive mine and never gave it much thought to look at it. Never had an issue.

 

[H3LZSN1P3R]

I just drive mine and never gave it much thought to look at it. Never had an issue.

Thats the best way, overthinking it usually leads to worrying for no reason

 

[John Jensen]

I am curious about this "passive regen" that keeps being mentioned. Is it really a thing?

Or is it just a loose term for when you work the engine towing at speed and for a time and the EGTs get hot enough to burn off the soot? If it is the first, then you would think there would be a record of it in the computer that the iDash or similar could pick up. If it is just a colloquial term for "hot exhaust" then no, I guess there would be no way to know when it is happening? Unless there is an approximate temp that it occurs at in which case, I could see it, since I display 3 different EGTs on the iDash.

Maybe someone can explain? In any case, it should not matter in my case as for the first 7 regens I had on 24 hour marks, I was towing the same or harder as this last time where it has gone on by the 24-hour mark without a regen. What I am saying is that I am sure my exhaust was just as hot during those seven 24-hour regens as it has been lately. Maybe even hotter during the 24-hour regens time frame as those were long trips in mountains and hot desert. This time when it skipped the 24-hour regen, I have been around home with easy, short, cooler weather tows.

EGT3 will go up during an active regen and a passive regen. If the truck is not in an active regen and EGT3 goes up you are probably in a passive regen. A passive regen begins when EGT3 hits 662 degrees. I've seen my truck's % soot level go down during passive regenning.

 

[CFE]

I must drive my truck like I stole it. No Regens yet with 5,000 miles or so

My wife thinks I only have 3 guns

I'm nearing 8k, daily driven since July with 2 days a week being a 2.5/3 hour drive one way....and no regen message as of yet.

 

[flan]

I'm nearing 8k, daily driven since July with 2 days a week being a 2.5/3 hour drive one way....and no regen message as of yet.

Have you had your EVIC display on the DPF screen the entire time?

 

[John Jensen]

I'm nearing 8k, daily driven since July with 2 days a week being a 2.5/3 hour drive one way....and no regen message as of yet.

I started tracking my active regens beginning with one at 5365 miles. Have had two since at 6967 and 7856 miles

 

[CFE]

Have you had your EVIC display on the DPF screen the entire time?

Not the entire time - I just "assumed" that a "regen" message would pop up while driving?

I started tracking my active regens beginning with one at 5365 miles. Have had two since at 6967 and 7856 miles

Is there a way to check the historical data log via alphaobd to see if/when regens occurred?