DPF Full: Causes, Repair & Solutions

Hello everyone,

I'm now actively participating for the first time, although I've come across your tips on Google many times in the past. Very competent - great! Last year, I bought VCDS here and used it to find an error in my first A4 B7.

Okay, I'm having a problem with my other A4 (B7 Avant 2.0 TDI 170 hp, year 2007, engine code BRD, 163,000 km). We've had it for 2 months, and as far as I can tell, everything is still original. It's showing the particulate filter symbol, the engine malfunction light is on, the glow plug light is blinking, and therefore it's only running in limp mode.

My wife called me from the highway, saying that the check engine light came on, and shortly after, all the other lights turned on, including the warning light. She still had about 290 km to drive to get home. So, my assumption was that the diesel particulate filter was full. I told her to carefully drive home at around 2000 to 2500 RPM (which is about 90 to 100 km/h, as it barely goes faster in limp mode). Hopefully, the filter would passively regenerate during the drive, and things wouldn't get worse, I thought.

Connected VCDS at home: Error message for the particulate filter, as expected. Hoses in the engine compartment, etc., showed no obvious abnormalities, as far as I could tell with my thick fingers.

Habe heute schon 4 Stunden in Netz nach ähnlichen Fehlern gesucht, aber nichts passt so richtig außer dem u.g. Linc.

Here's the log (first log before the trial deletion):
Saturday, January 9, 2016, 7:52:09:52443 PM.
VCDS Version: RKS 15.7.1.0
Data as of: 20150910.

Address 01: Engine Control Module
Label file: DRV\03G-906-018-BRD.clb
Control unit part number: 03G 906 018 AQ. Hardware: 03G 906 018 AQ.
Part and/or version: R4 2.0l PPD1.3 G 9973
Encoding: 0000072
Operating number: WSC 39900 136 86404
VCID: 74E07E8C1777F49E49-8020
"One error found:"
008194 - Particle filter, bank 1.
P2002 - 006 - Malfunction - Warning light ON.
Environmental conditions:
Error status: 11100001
Error priority: 5.
Error frequency: 5
Lost Count: 40
Mileage: 0 km
Time: 0.

Environmental conditions:
Speed: 2176 RPM.
Torque: 200.0 Nm
Speed: 0.0 km/h
(no unit): 0.0
Lambda: 221.0%
Pressure: 0.0 mbar.
Time: 359.4 s
Readiness: Not Available.

And some relevant measurement data blocks, I hope everything important is included.
Engine idling (relatively cold).

Address 01: Engine Control Module (03G 906 018 AQ)

16:27:33 Block 013: Idle speed control (fuel injection deviation).
-0.60 mg/H Einspritzm.-Abw. Cylinder 1.
0.77 mg/H Einspritzm.-Abw. Cylinder 2.
-0.64 mg/H Einspritzm.-Abw. Cylinder 3.
0.45 mg/H Einspritzm.-Abw. Cylinder 4.

16:27:33 Block 018: Status of Piezo Valves.
0. 0 Piezovalve, Cylinder 1, Status.
0. 0 Piezovalve, Cylinder 2, Status.
0.0 Piezo valve, cylinder 3, status.
0.0 Piezo valve, cylinder 4, status.

16:27:33 Block 067: Particle filter (exhaust values I)
157.0°C - Temperature before the turbocharger.
98.9°C - Temperature in the particulate filter.
59.9 mbar, differential pressure, particulate filter.
2 mbar offset differential pressure.

16:30:17 Block 068: Particle filter (exhaust values II)
221.9% Loading coefficient.
16.42 Ash content
-5.3% Ash content.

16:30:17 Block 070: Particle filter (regeneration status II)
00000000 Status 4: Regeneration.
362.8 s Regeneration time.
0.0 Unsuccessful regenerations.
0. 0 Successful regenerations.

16:30:17 Block 073: Diesel Particulate Filter (Vehicle Data)
27.6 liters, fuel consumption since regeneration.
372 km distance since regeneration.
8 hours since regeneration.


16:32:38 Block 080: Extended Controller Identification.
SJ8-FST 30.09.07 --H43--- 0415 0229 Identification

16:32:38 Block 084
221.9% Lambda
0.0% Lambda.
0 (no unit)
0 (no unit)

16:32:38 Block 091: EOBD Exhaust Gas Recirculation II.
100.0% Positive deviation from the rule.
-100.0% Negative deviation from the rule.
292.6 mg/H - Exhaust Gas Recirculation (Target Value)
1.0% deviation from the rule.

Engine off:

16:36:23 Block 067: Particle filter (exhaust values I)
97.8°C - Temperature before the turbocharger.
81.5°C - Temperature in the particulate filter.
Pressure difference across the particulate filter: 1.0 mbar.
2 mbar offset differential pressure.

16:36:23 Block 090: EOBD Exhaust Gas Recirculation I.
0 /min Motor speed (G28)
26.1 mg/H injection volume.
0.0 mg/H, Exhaust Gas Recirculation (Target Value)
00000000 Status: Rule violation.

16:36:23 Block 091: EOBD Exhaust Gas Recirculation II.
100.0% Positive deviation from the rule.
-100.0% Negative deviation from the rule.
0.0 mg/H, Exhaust Gas Recirculation (Target Value)
0.0% Deviation from the rule.

Es fällt in Block 68 der immense Beladungskoeffizient von 221% auf, aber der Aschegehalt ist mit 16 noch sehr gut. Mich irritiert, daß die Beladung bis aufs Zehntel exakt dem Lambdawert entspricht (Block 84), Zufall? Ich hätte es für einen Beschriftungsfehler gehalten, aber der Wert steht so auch beim Fehlereintrag. Laut log war die letzte reguläre Regeneration rund 80 km vor den Fehlermeldungen, soweit scheinbar i.O. Es sind aber 0 erfolglose und auch 0 erfolgreiche verbucht. EtThat's strange.

In my opinion, he shouldn't have been allowed to gain much speed in the middle lane during that highway drive. Passive regeneration should be completely independent of any control interventions and should always work, right? Or am I getting false readings? The differential pressure sensor is already the newer version 076..., and seems to be providing reasonably plausible values when stationary and when accelerating.
"However, I haven't been able to examine it in more detail yet. How exactly does the system calculate the loading coefficient? Is it based on the differential pressure? If so, could it simply be inserted and cause the system to go into emergency mode, even if everything else is fine?"

Can someone interpret the tolerance limits in block 91? Does that make sense? +/-100% seems a bit too lenient...
The fuel injection amounts don't seem to be perfectly accurate, but that hardly explains this error, does it?

Nach der Autobahnfahrt kann ich nicht glauben, daß der DPF so dicht ist und glaube an falsche Eingangsdaten. But where from?
There's a mention of software bugs in another forum, but why should that cause problems during normal operation right now? I can't seem to find my software version; where is it hidden?

Does anyone have a suggestion? If needed, I can also extract more data.

Thank you.

Andreas.

Hello.
Pressure 0 mbar, ambient pressure. The different values before/inside the particulate filter, as well as the 27.6 liters consumed over 372 km in 8 hours since the regeneration, also seem unusual to me. Are you consuming 7.4 liters per 100 km at a speed of 46.5 km/h? Is that city driving or traffic congestion on the highway?
haithamina

Good morning.

Quote:

She should carefully drive home at 2000 to 2500 RPM (approximately 90 to 100 km/h; it's unlikely to go much faster in limp mode). During this time, the filter should passively burn off

.
No, passive regeneration occurs simply through normal driving. If you drive in the area you mentioned, the exhaust temperatures will be too low for passive regeneration to occur. At the same time, however, very little additional soot should be produced.
A passive regeneration might occur when you accelerate up a highway incline in 5th gear with plenty of throttle. I would advise against any further driving with your DPF at the moment!

Quote:

Address 01: Engine Control Module Label file: DRV\03G-906-018-BRD.clb Control unit part number: 03G 906 018 AQ, Hardware: 03G 906 018 AQ. Component and/or version: R4 2.0l PPD1.3 G 9973 Encoding: 0000072 Operating number: WSC 39900 136 86404

Your software version in the engine control unit is 9973.

Quote:

16:30:17 Block 068: Particle filter (exhaust values II) 221.9% loading coefficient. 16.42 Ash content. -5.3% ash content

Neither the loading coefficient is plausible (active regeneration usually starts during operation at around 40%) nor the ash mass. This doesn't match the stated mileage. Either the mileage is incorrect, the displayed values are simply wrong, or someone has tampered with the DPF.

Quote:

A4 (B7 Avant 2.0 TDI 170 hp, year 07, engine code BRD, 163,000 km), which we have owned for 2 months

.
I'm afraid that, unless you've personally tinkered with various adjustment settings (stay away if you don't know what you're doing!), the mileage on the car might have been tampered with, or the engine control unit might have been flashed with incorrect data (bad tuning or faulty software). This should be investigated.
I am not aware of any instances where these incorrect values are caused by a specific faulty software version and are only displayed incorrectly.
Search the web for a newer software version for your engine control unit (using the VAG part number "03G 906 018 AQ" and then check if you can find a higher number than software version 9973).

Hopefully, it's just a faulty sensor preventing active regeneration, but that still doesn't explain the incorrect values appearing in measurement block 68.

First, considering the state of the exhaust system, I would remove the DPF and determine exactly what is inside. It's possible that the turbocharger's oil seal is leaking, causing the DPF to become clogged (which would require a new turbocharger). So, I would check how full the DPF is and what exactly is inside it.

Sure, here is the translation of the text from German to English:

"Background information:"
https://community.dieselschrauber.org/en/viewtopic.php?t=24243&highlight=dpf+reinigen

There are service providers that professionally verschandeln DPFs. You should contact a reputable one (search online).

Please provide the German text you would like me to translate into English. I will then provide only the translation, without any explanations.
- Readiness (posten!), here you can see if the AGR system is functioning.
- All (!) temperature sensors: This involves checking various sensor modules from the engine control unit (!) and verifying the values for plausibility: coolant temperature, possibly oil temperature, and all values from the exhaust temperature sensors.
- Check the charge air system for leaks (oil traces on the charge air pipes or in the intercooler indicate leaks).
- Values from the differential pressure sensor, see: https://community.dieselschrauber.org/en/viewtopic.php?t=24222

Please provide a complete vehicle scan.

The measurement blocks above 75 are rather uninteresting.

Good luck, Rainer.

Hello, thank you in advance for the suggestions. Special thanks to Rainer for the detailed comments (my remarks regarding these are below).
Despite my concerns, I drove the car again to collect some useful data for analysis. I'd rather not proactively remove the filter etc. (it's probably going to be a pain), only to later find out that a 30€ sensor was the problem.
For comparison, I took a drive in my other identical A4 (both with the BRD engine). It runs perfectly and without any issues. I warmed up both cars and then drove a short distance on the highway to perform the full-throttle test described, followed by some rural roads and city driving to identify any anomalies. I applied the same driving patterns to both cars. Let's see how I can upload this (DA-YA is the one that's working correctly, and DA-AP is the A4 with the problem).

The problem is that the defect triggers a limp-home mode at 2800 RPM, which prevents high temperatures; it might be intentionally limited. The shape of both Direct Drive System (DDS) curves looks plausible, but the DA-AP curve suggests a clogged filter (high mean level). What's surprising is that the other curve shows such high peaks, but in normal operation, it seems reasonable. I don't see anything suspicious in the values for exhaust gas recirculation, boost pressure control, etc. However, the boost pressure seems very high in the DA-YA reading (I would appreciate any comments on this).
My conclusion regarding the defect, with the caveat that I have limited experience with this: the filter is likely clogged. I may be imagining it, but it seems to be blowing out more than it should. Perhaps the turbocharger is indeed oil-leaky, as Rainer speculated. We're talking about the hot side of the turbocharger, right? Or is the oil being drawn in from the intake side and then partially burned in the cylinder before being blown into the exhaust?
Are there similar problems caused by the EGR system as well? They seem to be quite prone to issues.

Before I start disassembling everything, I wanted to try one more time to regenerate it. To do that, I have the following questions:
- I know that this can become dangerous with such a high load (over 200%). Surely it should be possible to do it in stages, by stopping after a few minutes while monitoring the filter temperature. Then, the combustion should quickly decrease to a minimum or even suffocate due to the lack of fresh oxygen. Has anyone had experience with this (a web search doesn't yield any results)?
- The control unit will likely not allow the action to start due to the load. How can I simulate a smaller value beforehand? As far as I've researched, this value is probably only calculated from the DDS value. And it's probably only read at a specific point in the characteristic curve (otherwise, the displayed load would constantly fluctuate in proportion to the measured value). The value in the measurement block is static; when and how often is it reset?

Here are a few more comments regarding Rainer's remarks:
- I don't know if anyone messed with it before, I definitely didn't, and it worked fine for the first 8 weeks after I registered it. The timing of the defect seems to be coincidental. The mileage might have been tampered with, but there are no other indications of that. It's unlikely anyone tried to modify it; it seems more like a typical family car, but who knows?
- I haven't found anything related to the charge air system so far. I even removed the lower panel. Is there a trick to checking it?
- Readiness habe ich nun auch nach der o.g. Trip:
Complaining about the AGR system, for whatever reason. It also releases exhaust gases that can be drawn into the ventilation system. Could that be related? I can't detect any leaks during a visual inspection with the engine running.
The Readiness system was also checked as a "pseudo-ASU" by the official TÜV (technical inspection agency) in November. So, everything must have been fine at that point.
09:18:16 Block 017: Readiness Code (EOBD)
00000000 CARB Mode 01 DATA A
00000110 CARB Mode 01 DATA B
11100000 CARB Mode 01 DATA C
11100000 CARB Mode 01 DATA D
Readiness Status: 00000000 00000110 11100000 11100000
Exhaust emission warning lights: Warning light OFF.
Remaining systems: Passed.
Fuel system: Passed.
Exhaust gas recirculation: Malfunction.
Number of OBD-II/EOBD error codes: 0.

- I only sent the scan of the engine control unit because I thought the rest might not be related. But maybe it is: Here are some error messages that I can only partially understand (the air conditioning error is probably due to the usual leaky pressure sensor).
Address 08: Climate Control/Heating. Label file: DRV\8E0-820-043.lbl
Part number: 8E0 820 043 BM
Part: A4 Climate Control Unit, part number 3233.
Encoding: 00000
Operating number: WSC 00000
VCID: 6DD66BE8275D255686-5160
2 error codes found:
00716 - Actuator for the air control flap (V113).
41-00 - Blocked or Unpowered.
00819 - High-pressure sensor (G65)
07-10 - Signal too low - Sporadically[/color]
Please provide the text you would like me to translate from German to English.
Address 46: Comfort System
Label file: DRV\8E0-959-433-MAX.lbl
Part number: 8E0 959 433 CM
Component: Comfort Device T23 4336
Encoding: 07008
Operating number: WSC 06335
VCID: 7EF45CA47A3BAECE2F-4B38
Subsystem 1 - Part number: 8E1959801H
Component: Törsteuer.FS BRM 0606
Subsystem 2 - Part number: 8E1959802H
Component: Törsteuer.BF BRM 0606
Subsystem 3 - Part number: 8E0959801E
Component: Törsteuer.HL BRM 0606
Subsystem 4 - Part number: 8E0959802E
Component: Törsteuer.HR BRM 0606
2 error codes found:
01336 - Corporate Data Bus Comfort.
80-10 - in single-wire mode - Intermittent.



Ich freue mich über anregende Kommentare. Thank you very much.

Andreas.

Hi,

The boost pressure, exceeding 2500 mbar, is normal for this engine. The pressure differential peaks are relatively high compared to other TDIs ( https://community.dieselschrauber.org/en/viewtopic.php?t=24222 ), and I don't know if that's normal; I haven't often worked with engines like yours.

The forced regeneration process might work – if it even starts. Still risky. I have no idea how to fake the load, as it's calculated by observing the differential pressure during driving. I don't think disconnecting the sensor hose is a good idea (due to the heat).

Loader: Both sides of the reservoir could potentially lose oil...

After a successful filter cleaning, I would continue searching for the faulty EGR valve and, of course, check for oil residue in the DPF pipe and on the exhaust side of the turbocharger.

Best regards, Rainer.

Hello, thank you again for the tips.
I've found a solution for regenerating a completely overloaded DPF, and so far, it seems to be working well. I'll describe it below.
The cause is still unclear. It's possible that oil entered the DPF because the oil level was slightly too high (up to the top ball on the dipstick). Unfortunately, the manual doesn't specify the difference between the minimum and maximum levels (this used to be standard, but I couldn't find anything online). It's also possible that the turbocharger has a slight leak. However, I removed the intake hose when the engine was cold, and it rotated easily, so at least the shaft doesn't show any signs of wear that would cause high oil consumption. I haven't found any leaks in the pressurized intake system (which would cause soot) either.

My question for today: If the DPF is potentially clogged due to oil or a leaky intake system, why doesn't the engine control unit (ECU) initiate a regeneration process during the drive? For reference: the first time it clogged, it was also during a highway drive or shortly before, and the ECU did nothing other than display a warning message beforehand. If I see how quickly it can burn itself verschandeln even in city traffic, when it chooses to (see below), it doesn't seem to fit together.

How can I clear the DPF without removing it? It's been extremely cold outside for days, and I didn't want to remove it anyway, as long as there were better alternatives available.

Just a reminder: A4 TDI 2.0, manufactured in Germany. The DPF (Diesel Particulate Filter) reached levels exceeding 200%, seemingly without a clear cause, and after further test drives, it reached 250%. All signals were plausible, and the Audi was in a limp mode. The forced regeneration was also locked, presumably for safety reasons.
I was planning to do a partial regeneration if it got too hot. I'm quite sure it will stop quickly if I turn off the engine (due to lack of oxygen). The combustion should then be extinguished.
It is known that the loading value is calculated based on the differential pressure and other parameters. However, how this calculation is performed is unknown. So, I disconnected (and sealed) both hoses from the differential pressure sensor and went shopping, keeping VCDS active to monitor the system. And lo and behold, the loading value continuously decreased, almost linearly, as long as the car was moving. When the car was stopped at a traffic light, nothing happened. After about 7 km of city driving (with the temperature in the DPF below 300°), the loading value reached approximately 60%, the flashing light went out, the limp mode deactivated automatically, and the car started running somewhat normally. However, it was still quite sluggish, so the filter was likely really clogged, and it wasn't a miscalculation. The loading value decreased to 20%, and then it stopped.

After things looked much better, I briefly got onto the highway to try to bring the filter temperature up above 450°C. However, nothing really happened. So, I reconnected the differential pressure sensor normally at home and started a forced regeneration using VCDS. Unfortunately, the turbocharger then started to lose power. Two hours later, I drove to the store with a slightly warm engine, and the differential pressure was still high, at 300 mbar during slight acceleration, and the response was still sluggish. After only 1 km in city traffic, I suddenly saw temperatures exceeding 600°C, and it was emitting a lot of smoke from the back. So, the forced regeneration that I had started two hours earlier had become active (it seems to retain the setting once triggered). Instead of parking, I continued driving for an estimated 2 km (no more than 5 minutes!). Then the temperatures dropped again, and the load was only a few percent. The engine performance returned to completely normal!
I wouldn't have expected that to happen so quickly. Since then, I've driven 175 km, and it's been working perfectly. For a while, the load was around 5-10%, and it even decreased while driving, although the DPF temperature was only around 250° (which should be higher for it to regenerate).

Now I'm back to almost 40% loading, which is too much for the relatively short distance. So, the cause hasn't been found yet. But now I at least know how to force a regeneration of the overloaded filter. If you want to try it: with absolutely no liability on my part! And please always do it with VCDS running and monitoring the temperature! If anything gets too hot, turn off the engine! Better than having to remove it...

Hello, here's an update after a long time.
What is likely contributing to the problem for me are increasingly carbon-fouled injectors. It automatically regenerates every 300 to 400 kilometers, which seems a bit too often, although the proportion of city driving is also high.

However, I'd like to add a note regarding the "tricky" forced regeneration described above: as far as I've observed, this only works if there are no error codes stored. So, if in doubt, clear the memory beforehand. I recently had to repeat the process as described above, and I repeatedly received the message "Control unit accepted coding" (or similar), but nothing happened (the engine was warm). Only after clearing an old AGR error code did the regeneration process start as usual. I also have the impression, although I'm not entirely sure, that it also prevents the regular (active) regeneration during normal operation if there are any error codes stored in the control unit. This can then lead to overfilling, the DPF light illuminating, and eventually to limp mode.

Regards,

Andreas.

Hello Andreas,

Quote:

I also have the impression, but I'm not entirely sure, that it also refuses the scheduled (active) regeneration during normal operation if there is any error stored in the MSG.

Depending on the error and the engine control unit, your impression is correct. So, if the normal regeneration process is no longer working, first look for errors that might be preventing it. Be aware: Even a too-low engine temperature due to a faulty thermostat can prevent regeneration.

If an unfavorable driving profile (e.g., short trips) is added to the mix, where passive regeneration is not possible (i.e., without the engine control unit taking any action), the DPF will inevitably become clogged.

Best regards, Rainer.

Hello Rainer,

Thank you for the feedback. That definitely works.
Officially, the only option is to have the DPF regenerated, which is an expensive process. Alternatively, you can try the trick described above.
Last time, the filter was definitely overloaded by more than 200%, and it took over 5 minutes for it to cool down to normal temperatures again (make sure to have the passenger monitor the temperatures!). But it seems like everything is working now.

Regards,

Andreas.

Heiner111 wrote:

What is likely contributing to the problem for me are increasingly carbon-fouled injectors. It automatically regenerates every 300 to 400 kilometers, which seems a bit too often, although the proportion of city driving is also high.

I can highly recommend the products from Lambda. So, in your case, Tank Diesel.

To verify the possibility of mileage manipulation mentioned earlier, I would use the assistant function in VCDS. It immediately detected the manipulation on an A6 a few days ago. However, the vehicle was not located in Germany (just as a note).

Are you following this?

Quote:

Readiness Status: 00000000 00000110 11100000 11100000 Exhaust emission warning lights: Warning light OFF. Remaining systems: Passed. Fuel system: Passed. Exhaust gas recirculation: Failed

If the AGR (Abgasrückführung) system is not working, it will prevent active regeneration.

Addition to VAG-Driver's tip: Apparently, the mileage cannot be verified on the ECU (Engine Control Unit) of the BRD model (and presumably similar models as well). In my V6-TDI Cabrio, this is possible, but unfortunately not in this case.
"Thank you anyway!"

Hello.

I am interested in knowing if a solution has been found for the problem described, where the DPF in this Audi with a BRD engine is showing a rapid filling rate, even though there is no apparent reason for it.

Wir haben den gleichen Wagen mit ganz ähnlichen Problemen. Es wurde bereits der zweite neue DPF verbaut (allerdings nicht original sondern Nachbau. Furthermore:

- New differential pressure sensor (Bosch).
- New turbo.
- PDE unit with only 20,000 km mileage, replaced as part of a recall.
- New LMM.
- Aral Ultimate was used for testing (as it's supposed to produce less soot).

The engine is running normally and has power, starts well, but it still goes into limp mode after about 150 km of city driving and 250-300 km of highway driving. This means the engine warning light comes on, and the glow plug symbol illuminates. Even if you try to perform a forced regeneration as described in the manual and drive accordingly, this condition persists. You then need to use a diagnostic tool to address the issue.

The car has already been checked by a Bosch service center and Audi. Audi installed the latest software and stated that no errors could be detected, although there is evidence of excessively rapid charging.

Initially, Bosch stated that the back pressure in the exhaust system was too high and that an original DPF (Diesel Particulate Filter) was absolutely necessary. However, they later corrected themselves, stating that the back pressure was actually okay.

"Does anyone have any ideas? Could it actually be due to the possibly differently constructed aftermarket DPF, or where is too much soot being produced? Or is the car receiving incorrect data from somewhere?"

Thank you in advance.

Would have, could have, would have...
Please attach an initial scan of the document first, and then I can assist you.

Hello, could it be that he's using too much oil (due to issues like piston rings or a head gasket, etc.)?
This could explain the rapid degradation. Otherwise, they seem more robust than I thought. But even then, it must automatically regenerate on a schedule according to the D-printer's specifications (and it does in mine, despite the moderately increased oil consumption)!

Or is there another engine fault occurring that doesn't seem to be related to exhaust emissions? In that case, the regeneration process will likely be suspended until the system goes into limp mode. In my case, for example, the connector on the EGR valve had a loose connection. That's enough to disrupt the normal regeneration process.
As my previous speaker mentioned: be sure to read the error memory according to the Motor Vehicle Act (MStG)!

Regards,

Andreas.