Ranger Mods

Does anyone know the programming behind DPF regens? I’m having issues with short km between regenerations even though driving style wouldn’t correlate. To put into perspective driving 500km mainly on the Hume hwy resulted in 5 regenerations.

The closed loop soot calculation increases much quicker than the open loop. According to the workshop manual there is only one sensor for the differential pressure, so how does it calculate the differential? Is there a sensor further downstream in the exhaust that it uses? Or is there a figure that the computer referenced against the measured value?

Trying to understand the root cause of my issue, whether it is sensor related or the physical DPF is on its way out, or otherwise!

Cheers

Pressure sensor on each side of the DPF.

Only Ford engineers can answer the algorithm used for when a DPF burns. There are a ton of factors and all are not entirely known.

Thanks. Do you happen to have a diagram illustrating the locations of the pressure sensors? I know the location of the one that looks like it is just prior to the DPF (in the side of the DPF located about half way down) but where is the second?

Also, do you happen to know what value pressure differential is one of the inputs to trigger a regen?

Thanks!

Here viewtopic.php?p=19602&hilit=Dpf#p19602

????, (i assume you have a name)
I've seen that an EGR stuck open a bit will result in very frequent DPF regens.
I'm in Canberra and can do a comprehensive data log for you but not until next week (probably need up to about 2 hours driving). PM me if you want to do this.

Thanks Ian,

I'm planning to do an EGR / intake manifold clean this week or next and see what effect that will have on my regen cycle. If it doesn't improve I'll be in touch!

Cheers,
Dean

Dean,
You should be able to see the EGR Commanded & Actual using FORscan, so do a before and after check. The issue might be more sinister, but start with the 'easy' (and cheap) stuff.

On a trip to Alice Springs I am noticing a burn is happening between 52 & 58% and burning off right down to 10%
Towing a van certainly helps to get the diesel working
In the city it doesn't burn until it reaches 100% then only burns down to around 25%
With the van removed at Alice it is like driving a V8, incredible response once the diesel has had a good workout

Long winded post but hoping to get some ideas from the brains trust. After completing the EGR and intake manifold clean, as well as an intercooler flush and new boost hoses, it has not fixed my issues with DPF regenerations.

EGR is closing properly. MAF, MAP sensors appear to be working correctly. Same with EGT sensors.

I haven't tested the differential pressure sensor yet, it is the "DPFP11" type sensor which references the pressure upstream of the DPF against atmospheric pressure (which in itself is an issue). I live in the hills just outside Canberra so my regular commutes have me going from 860m ASL to ~580m ASL, which is a difference of roughly 3.1kPA that the DPF will see as "increased soot buildup".

In particular, there is a hill roughly 850m distance that has a rise of approx. 80m. 80km/hr zone. In this short stretch of road, my closed loop soot level increases by 5%.

I have never seen my open loop soot level above 25%, and even that was an outlier. Generally, the closed loop soot level will reach 100% whilst the open loop is in the 10-20% range.

One thing that is strange is that in Forscan (and Torque Pro), the differential pressure PID is constantly 0. The only DPF pressure PID reading I get is from DPF Inlet Pressure, which lines up with my type of sensor, however doesn't explain why the differential pressure PID is always 0 given it measures against barometric.

The thing that confuses me the most, is that I get better distance between regens when I am doing my normal runs into Canberra and back (mainly 80km/hr zones, a few stops, a little bit of 60km/hr). I average around 200km with this type of driving, although I have (once) gotten up to the 400km mark.

When I hit the freeway (110km/hr), I get 100km between regenerations, the maximum I've gotten between regenerations is 150km.

One final thing - I never noticed a DPF regeneration occuring until I had an issue with my turbocharger actuator. I then started paying attention to EGT, soot % etc to know when a regeneration is taking place, which is how I picked up on the frequency of the regenerations. So it is a big unknown whether I had the same frequency regenerations taking place prior to having the turbo issue, and if I did, whether that was the cause of the failing actuator (the frequent heat from regenerations that goes into the engine bay surely is not great for electronic components!)

So, things left on my list to check are the differential pressure sensor and injectors. Outside of that, I'm thinking a professional clean of the DPF.

Has anyone had similar issues? Especially around worse regeneration "economy" on highway?

Being you did not have data before it will be difficult to make any assumptions. The PCM will be be using the MAP sensor for barometric pressure so it will be taken into account.

Being the PCM will choose the optimum time for the regeneration of the DPF. Under normal operating conditions the regeneration process occurs when the PCM has calculated that the DPF requires regeneration and that predetermined vehicle conditions are met (for example coolant temperature, vehicle speed and engine load) of which the entire algorithm is unknown.

Quote "One final thing - I never noticed a DPF regeneration occurring until I had an issue with my turbocharger actuator. I then started paying attention to EGT, soot % etc to know when a regeneration is taking place, which is how I picked up on the frequency of the regenerations."

Are you reading too much into it, are you looking at too much data that you did not do so before without directly comparing to another vehicle?

References.
viewtopic.php?p=16429
viewtopic.php?p=18792

I would say that there is an issue even though there are no DTCs. The PC/ED states regens occur between 97km and 805km. Based on my driving style (mainly cruising at speed), I fail to comprehend how I’m at the lower end of those figures.

My primary concern is that the frequent regenerations lead to premature failure of the turbo actuator, and I’m not going to be stoked to drop another $2k in the near future on a new turbo again. Thus trying to find the root cause.

Dean,
I'm not sure you can draw any reliable relationship between the turbo VGT actuator life and DPF regen. Yes, the exhaust temp is higher during regen but I wouldn't have thought it would impact turbo component life given the regen should stay under 650C. When graphed, does the EGRT1 reading look sensible?
If you want me to use my tools to do some logging, and compare to my PX3, I'm home this weekend.