DPF Active regen wont start

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Zekar
Posts: 4
Joined: Tue Feb 09, 2021 7:48 pm

DPF Active regen wont start

Post by Zekar » Sat Apr 03, 2021 9:22 am

Hello.
I have a problem.
Yesterday I had 100% on VAGDPF App and went for a drive (i drove for 60kms).
Input/Output gas couldn't reach more than 350°C.
Only once it reached 400°C when i drove 140km/h (dpf icon went to light red and showe -19mg/km).
Could it be faulty differential pressure sensor?
It looks like something is blocking DPF from turning on regen process.

Now i have 108%.
Screenshot below.
Attachments
Screenshot_20210402-192244_Gallery.jpg

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admin
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Re: DPF Active regen wont start

Post by admin » Sat Apr 03, 2021 5:39 pm

In this condition, the ECU should try to force the regeneration as soon as possible after the engine start, it's strange that this doesn't happen.
The regeneration duration field shows 42 minutes so it seems that the ECU has started the regeneration. If you see the input gas temperature under 400°C for long time while driving, the regeneration can't really start. The input gas temperature can reach 650-700°C only if the post injection values are more than 0 for many minutes: have you checked those values? Are they near 0?

Previous regenerations have been completed correctly?

Zekar
Posts: 4
Joined: Tue Feb 09, 2021 7:48 pm

Re: DPF Active regen wont start

Post by Zekar » Tue Apr 06, 2021 11:30 am

Last time regen was fine.
Then i removed EGR(with software change)
Here are screens from today

3 gear 80km/h

and
4 gear 130km/h
Attachments
Screenshot_20210406-092024_VAG DPF.jpg
Screenshot_20210406-092229_VAG DPF.jpg

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admin
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Re: DPF Active regen wont start

Post by admin » Tue Apr 06, 2021 5:09 pm

Was the regeneration finished? You can verify this checking the regen duration value, it change to 0 when finished.
And the soot mass should be between 2 and 8 grams.

Zekar
Posts: 4
Joined: Tue Feb 09, 2021 7:48 pm

Re: DPF Active regen wont start

Post by Zekar » Sun Apr 11, 2021 1:36 pm

No i can't finish the regeneration. Because i can't get the temperatures high enough.

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admin
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Re: DPF Active regen wont start

Post by admin » Mon Apr 12, 2021 11:55 am

Something is clearly working wrong. I see little reductions in your pictures, but not enough to reduce the soot mass to the common value after regeneration.
In this condition, the soot mass increases continuously and the DPF will be clogged soon. When the ECU detects a too high soot mass value, first will inform you of the problem with many warnings, but if the value will not decrease, it will activate the recovery procedure reducing the RPM and the engine power.
I suggest a technical check as soon as possible. Maybe it's only a faulty sensor, but it's better to check.

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DesmondNam
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Post by DesmondNam » Mon Sep 27, 2021 7:00 pm

A good indication if the dpf internals have been removed could be to check the end of the exhaust - on the 2 C5s I have had with a dpf, inside the end of the exhaust has been clean whereas other cars without a dpf, the exhaust has been covered in soot.

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