I just finished a trip towing and the truck performed very well. But it is frustrating to be travelling along for some time with about 15% on the DPF, 750-800° on EGT4, 65mph and the so called "mandatory 500 mile" regen kicks in. The DPF burns to 0% in about 5 miles, but the regen cycle continues burning the clean DPF for 20 miles total!! This happened twice, though the second time it only lasted about 10 miles. This has happened on other trips, but I decided to say something this time. Any body else seeing this unnecessary behavior?

 

Yes, I have seen it happen. I was hoping the regen strategy would have been update with this jack hammering tsb. I have seen it start with the CTS showing like 30% DPT load.

 

Even for a needed regen with the DPF at 100% it burns down to 0% and continues to burn the clean DPF for additional time. Seems like simple logic: if DPF < 5% then stop regen; if DPF < 5% then inhibit regen = fuel economy. Sorry. Driving the high deserts of the 4 Corners Region one has time, lots of it, to notice these things and wonder about the wisdom of Ford's automotive logic.

 

Just my thoughts, but I believe this logic has more to do with residual ash then soot in the DPF. It is the residual ash that plugs the DPF and it depends the type of sensors that your truck uses to detect and monitors restrictions is the DPF. The Fords use different sensors for a given model year. So I believe that your truck might not really be helping to reduce soot, it might be trying to reduce ash. My friend's 6.7 monitors exhaust back pressure and my 6.7L truck has a differential pressure sensor system, so the PCM value that is used in the equation of your monitoring device is relative to the one that wrote the equation. I wrote the equation that I use, so either right or wrong it means something to maybe only me. The equation I post on threads are in percent. I monitor bit "A" and "B" in hexadecimal values so when my display shows the value of C2, my truck's PCM will start an Active Regen if all the other parameters are met.

In short!!
I read a few years ago on the EPA link of papers sent in to by Ford about the DPF system (At the time I wish I saved the link). It was when I tried to figure out "Grams per Litre" of soot. That is why the Soot % PID equation in Torque Pro was created so most of the folks could understand. These units are relative and come from the same computer output value so take these values as with a grain, this means something but not the whole story.

 

Just thinking. If the residual ash is still loading the DPF, there should be a differential pressure generated because of that ash and the DPF % loading should be greater than 0% ..... which it is not ..... for 20 miles. I guess one way to stop the unnecessary regen is to pull over to the side of the road, shut the engine down, and stretch your legs for a while.

 

Interesting

Just thinking also. The pressure differential of soot plugging the substrate in the DPF is a lot higher then residual ash sitting in the bottom of the DPF.
So my way of thinking is 100% Soot is not 100% Ash.
So is the truck in Active Regen for Soot reduction, I don't think so. Is it in Active Regen to reduce ash, I believe so.

So my logic is, Ford's programming to put the truck into Active Regen with the Soot Percent reading low is because it has to, not because they want to for no reason.
Can you imagine a dash message showing " Cleaning Soot from the SCR System" and the shortly after a message "Cleaning Ash from the SRC System"

FYI:
Two co-workers with dodges that use their truck to drive back and forth to work a and one snow plows had to replace the plugged DPF at the cost of $3500 (Well one deleted his). My point is that they kept interupting their trucks when it was trying to Regen.
I'm not an expert, but I would need more information to say that a Regen is unnecessary!! I know if I would pull over to stop a regen it would start up again shortly. There are times I see 150 Miles subtracted from the DSLR PID when I interupt an Active Regen started by mileage and not Soot.

Not sure what device you use to monitor but I mostly use Torque Pro. Most of the PIDs I use were created by me, a fat old guy so you have to take it with a grain and why I find your post interesting.

 

My truck has 121,000 on it and I've never ever seen the dpf percentage below 20%. It routinely cleans from 100 down to 35, 30, or 25% but never zero. Sometimes it will clean when it reaches 85% and stop at 45%. Appears to be completely random as all I ever do is cruise at 72mph and watch it.

I think as the system ages it loses the ability to get down to zero but I don't know for a fact.

 

I had the exhaust filter screen activated on my 2016 when it was 3 days old. It never regenerated before the screen went from 95% to "Full." However, once it did start the regen, it never once cleaned down below 20%...even when it had every opportunity to continue the regen as I was on the highway for many more miles after it ended the regen.

My theory is that when the screen reads "Full" the DPF is actually not full, or the truck wouldn't be running. Maybe when it gets down to 20%, it really si closer to completely clean.

But then of course, some of you guys have seen 0%.

In my mind, the 2011-2016 trucks still beat the 2017 I have now, which no longer displays any messages regarding the start of a regen...which I hate.

 

I have seen this type of regen activity also: not burning the DPF to zero, but stopping at 15-20%. A large fraction of time it burns to 0% and continues burning for 10+ miles. The mysteries of Ford logic.

 

I would like to know how the screen reported DPF % is calculated. Looking at the PIDs reported by ForScan, there is at best a loose relationship. On my '15 truck, the dash screen % only goes up (even when 'passive regen' should be happening), always enters a regen within a minute of hitting "Full", and then burns down to about 30-35% before turning off regen. It will continue to coast down to 20 - 30% with regen inactive but while the DPF is still hot (>600 or so).

In contrast, the ForScan reported soot load (g/L) and percentage will go down in 'passive regen' (while the dash screen continues up). The load will get to between 3.0 and 3.5 g/L and then regen will start. It will burn down to 1.0 or a little lower.

It is my belief that the DPF % reported on the dash has been dumbed down to make it less confusing to drivers.

 

The DPF% screen is a combination of soot load, and mileage, whichever is higher. I routinely monitor it, and Torque Pro, and when I am not towing, and get regular regens based on soot load, my TP gauge and the ford DPF % are almost identical. However, when towing heavy, and getting passive regens, my TP soot load & % might be 20%, but the ford DPF shows 80%, and thats because DSLR(c) is up around 350-400 miles. It never burns down to 0%, usually quits around 25%, and burns down to 15%.

As far as comments about regen frustration, my reaction is to just not worry about it. it is what it is, and those of us on the forum are just well, more **** about all this than the normal driver/owner.

 

Beginning to think that we are being lied to on the gauges and the computer is seeing something else. I have only been down to 20% as well, but most of the time I don't get to do a complete regen.

BTW, on the 2017 that is bunk. We should be getting more info, not less.

 

It's a double edged sword. If the machine is working well .... not to worry. But the operator in me has to ask 'why' when certain parameters are observed that don't sense.

 

Add me me to the list of confused....

Just finished a 600 mile trip in central Idaho towing my 27 foot bumper pull. not sure of my exact weight but somewhere near 8000 pounds. My EGT's were constantly between 650 and 850°F. The monitor I am using is called DashBoss and it shows soot level. My soot showed an initial value of 1.75 and worked its way down to 1.3. The exhaust screen started at 35% on the trip. The whole time the exhaust filter screen on my dash continued to climb. About 250 miles into the trip the exhaust screen went to full and an active regen started. It did not last long and the percentage on my dash counted down quickly stopping at 30%. My soot went from the 1.3 to just below 1. I thought this was odd. On my way home EGT's were still between 650 and even 900 at times. The soot stayed below 1.5 the entire time. However, the exhaust filter screen on the dash continue to climb. When I got on the interstate I had a major headwind and EGT's were in the 900s. The soot level went down to. 89. The exhaust filter screen on the dash continue to climb and hit Full and another active regen started just before I pulled into my house. I then had to drive around for the active regen to finish which also did not take long. On this one the exhaust filter stopped at 15%.

Does anybody have any ideas on why this happened?

 

Khena....sounds normal to me....Ford has it programmed to regen at 500 miles or when DPT is considered full from the soot load or pressure or some other parameter.

Best to not worry about it. You are not going to change it unless you can program you PCM or do a full delete.