Page 1 of 1

DPF Active regen wont start

Posted: Sat Apr 03, 2021 9:22 am
by Zekar
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.

Re: DPF Active regen wont start

Posted: Sat Apr 03, 2021 5:39 pm
by admin
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?

Re: DPF Active regen wont start

Posted: Tue Apr 06, 2021 11:30 am
by Zekar
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

Re: DPF Active regen wont start

Posted: Tue Apr 06, 2021 5:09 pm
by admin
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.

Re: DPF Active regen wont start

Posted: Sun Apr 11, 2021 1:36 pm
by Zekar
No i can't finish the regeneration. Because i can't get the temperatures high enough.

Re: DPF Active regen wont start

Posted: Mon Apr 12, 2021 11:55 am
by admin
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.

-

Posted: Mon Sep 27, 2021 7:00 pm
by DesmondNam
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.