CFFB: Regeneration will nicht enden | Posts 32+

Hi,
Particulate filter: Pressure difference offset: 0 hPa.
Particulate filter: Oil ash volume 0.00 l.

Best regards.

Sorry if something is missing from the text here. I posted directly instead of quoting, but hopefully I've fixed everything now.
hg
Herbert

Hi,

Quote:

... Particulate filter: Pressure difference offset: 0 hPa. Particulate filter: Oil ash volume 0.00 l regards

I had suspected that.

Quote:

... The differential pressure was always too high until the DPF was cleaned at the front, behind the engine. Therefore, the original DPF has been reinstalled, which a cleaning device specifically purchased for this purpose deemed to be okay after cleaning, although it is not possible to reliably distinguish between ash and soot. During reassembly, it was then discovered that the exhaust flow was again unduly restricted, which was due to the SCR catalyst. Now a new KAT has been installed, and now it seems like everything is okay again.

The oil ash volume would have had to be set to a minimum level of 70,000 to 100,000 kilometers. The cleaning cannot be complete.
The differential pressure is likely being measured as a soot load based on the ash volume.
"Corked" could be a good fit for the condition. If everything is working, just leave it as it is. Playing ping-pong with your workshop, with you as the ball, achieves nothing.
hg
Herbert.

Hi Herbert,

To be honest, I don't quite understand the logic of your comment. Could you please elaborate and provide more details? Are you suggesting that a "recycled" DPF, however it's processed, can never be considered new, meaning new in the sense of having a zero oil ash volume?

In what ways does resetting to a default state negatively impact currently ongoing regeneration processes? Which sensor values are currently too high or too low, indicating potential problems in the future?

Not many kilometers have been driven yet. Would it be advisable to make an adjustment now? Can't I do this myself?

I probably won't be able to assess whether this "if everything goes according to plan" is accurate until the time when things start to go wrong. But then it will probably be too late?

Thank you in advance, Best regards.

PS: You correctly restored the post from today at 10:11 AM. With the exception of "mfg", which originally had "LG" .

Hi,
I'll try to shed some light on the matter for you.
Differential pressure measurement cannot distinguish between pressure differences caused by ash buildup and pressure differences caused by soot buildup.
The ash loading value is calculated based on mileage, and is specific to each engine. Therefore, a km value is also entered during the adaptation process.
The soot load is determined once based on fuel consumption (value: calculated soot load) and once based on the differential pressure (value: measured soot load).
If either of the two values exceeds the threshold for field regeneration, the regeneration process is triggered.
Unexpectedly high ash loading is interpreted as soot loading. Regeneration cycles occur with an incomprehensibly high frequency. In the worst-case scenario, the over-firing might go unnoticed because the calculated value looks perfectly fine.
That's exactly what happened with your engine just now.
With a DPF that has been regenerated through flushing, not all of the ash residue is removed.
hg
Herbert.

Hi Herbert,

Thank you very much for your detailed answer! I now understand that my DPF, which is effectively no longer new but is being presented to the system as new, requires regeneration less frequently than it actually needs to, which carries a significant risk of permanent clogging, sooner or later.

Then, should the offset in the differential pressure be adjusted upwards, and/or should the ash volume be set to a realistic value? Can only the workshop do that?

What I still don't understand is this: You state that the measured soot mass is determined from the differential pressure, while the calculated soot mass is derived from the fuel consumption. However, when I look at my regeneration log from the last time, the value for the measured soot mass remains almost constant during the regeneration process (while the differential pressure decreases), whereas the value for the calculated soot mass decreases significantly. How is that logical?

Thank you in advance. Best regards.

Hi,
I can't explain it any better than I already have. Think about it carefully again.
The ash content value is incorrect. In your otherwise incomplete record of the regeneration process, it is already noted that a differential pressure of 200 mbar is reached.
If you're already creating logs, then include a snapshot with the static DPF data (in the order relevant to my CJCD: loading limit for field regeneration, loading limit for service regeneration, loading limit for overload, fuel consumption since last regeneration, kilometers since last regeneration, offset for differential pressure, oil ash volume, oil ash mass, calculated soot mass, measured soot mass, vehicle mileage), and secondly, a CSV recording of the data during the drive. You can find specific information about what data is needed here: /viewtopic.php?t=24222 and here: /viewtopic.php?t=25999.
You have to humble yourself; no one can do that for you.
hg
Herbert.

Hi,

Thank you for the response! I don't want to give the impression that I'm just asking questions here out of laziness, hoping that others will do the work for me. If it seems that way, please accept my apologies.
I had been thinking about this before the posts appeared, even though it might not seem that way. Apparently, my efforts were unsuccessful. I cannot understand why the value: soot loading remains constant during the regeneration process, when it is calculated from the differential pressure, which, on the other hand, decreases.

Quote:

Take a snapshot with the static DPF data

. Then, record this snapshot during the regeneration? Or after completion (which, in my opinion, doesn't make sense because all entries related to "since the last regeneration" will be 0)? Taking it directly before (which would be desirable) is not possible because I don't know when the regeneration will start.

Thanks for the tips, best regards.

Edit:
In the attachment, you'll find the static values from earlier. Rainer suggested that I could save the parameters so I wouldn't have to search for them every time. How does it work?

Hello,

Find and save VCDS measurement values.

I'm unsure why the "measured" soot mass remains constant during regeneration, assuming I've understood the situation correctly.
Apart from that, the ECU cannot measure the soot mass because it lacks a weighing device.

When it comes to both terminology and functionality, a certain degree of skepticism is always warranted, as much of it originates from various sources, some from the ECU itself and some from VCDS.
Incorrect terms or values occasionally occur, although rarely.

If one of the two "soot mass values" decreases during the regeneration process, that would be acceptable to me.
It's possible that's not the case, however. The fact that it goes back is a noteworthy detail.

Regardless of the ECU, the DPF can only contain what actually entered it, and not what the ECU estimates might be present.

Has the oil consumption been checked by you and found to be acceptable? I have no idea if a dipstick that is too short for the engine could be from a different vehicle. As you can see, there are many possibilities. Now, with the cleaned DPF, let's see if things stabilize and are okay.

Best regards, Rainer.

Hi,

Thank you very much for the reply!

The issue with the oil level is bothering me. Usually, you're happy when the oil level doesn't decrease too quickly. I've never changed the oil myself on this Sharan. And I had to search for a long time in the manuals to find the required amount of engine oil: The internet says 4.3 liters, but I can't find that amount anywhere in the manuals, even though there are plenty of notes about service intervals, standards, and normal consumption values under the relevant section in the owner's manual.

Assuming the engine oil level was 0.5 liters above the maximum limit, would this explain why the DPF was clogged?

As a result, many questions arise: Is there too much engine oil since the last oil change (a year ago), or has the level increased due to oil dilution? Could it have been more than 0.5 liters too much, which ended up as soot in the DPF, leading to the fatal consequences described here?
I cannot answer those questions because, unfortunately, I did not perform the oil change myself.

Hi,

Now, there is an error (see below) stored in the engine control unit. How should this be handled? Background: DPF was cleaned, new SCR catalyst was installed.

Sure, here's the translation:

"Thank you in advance. Best regards."

Please provide the German text you would like me to translate into English.
Sure, here is the translation of the text from German to English:

"1 error found:"
15733 - SCR NOx catalyst, bank 1.
P20EE 00 [101] - Efficiency too low.
unconfirmed - checked since last deletion.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 2
Mileage: 129,274 km
Date: 2023.12.26
Time: 22:01:41

Motor speed: 1834.50 rpm.
Normalized load value: 0.0%
Vehicle speed: 100 km/h
Coolant temperature: 87 °C
Intake air temperature: 10 °C
Atmospheric pressure: 970 millibars.
Voltage at terminal 30: 13,900 V.
Lost count after OBD: 40
Long-term adjustment of reducing agent dosage: 1.00.
Measured NOx conversion: 0.166
Calculated NOx conversion efficiency: 0.890
NOx conversion efficiency threshold: 0.300
Current temperature in the NOx reduction catalyst: 295.8 °C.

Readiness: 0 0 0 0 0
"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Ein leichter Wind weht durch die Bäume, und die Blätter rascheln leise. Es ist ein wunderschöner Tag, um draußen zu sein und die Natur zu genießen."
==================================================

"The sun is shining brightly, and the birds are chirping cheerfully. A gentle breeze is blowing through the trees, and the leaves are rustling softly. It's a beautiful day to be outside and enjoy nature."

Hello,

I feel like we're going around in circles here, discussing obvious things. To check the engine oil level, there is a dipstick, which can be identified by the orange plastic ring.

It's really exhausting. In the morning, the sun rises, and in the evening, it sets.
Do I really have to say that, when the SCR catalyst has a low efficiency, the measured values, the measurement algorithm, the hardware (catalyst), or the reducing agent could be to blame?
What's so incredibly difficult about not trying everything randomly, like a random number generator, but instead eliminating possibilities one by one?

Why are hints, such as comparing it to a functioning, identical vehicle, being ignored? Again and again?

You turn 360 degrees.

Best regards, Rainer.

Hi,

Should I have given anyone the impression (through any written words) that I would be unable to measure the oil level, I sincerely apologize. I can measure the oil level, and I can do it completely on my own.

I don't know why there was too much oil in the engine (something I only recently noticed).
If I had been capable of doing the oil change on the Sharan myself, I would have put in exactly the right amount of oil. There's no need to dwell on my lack of skills here. There are (especially older) vehicles where changing the engine oil is no problem for me at all. Unfortunately, with the Sharan, this is not possible for various reasons (it's likely that some of these reasons are also related to economic considerations, specifically regarding after-sales service, where the accessibility of the components I need to access is a key factor).

I also don't know if the measured (apparently low) NOx conversion rate is related to this. And since I don't know that much, I'm going to be upfront and ask about .

Sure, here's the translation:

"LG" translates to "Best regards" or "Sincerely" in English.