AdBlue error keeps recurring

Hello fellow sufferers, I also drive a 7N model, manufactured in December 2010, with a CFFB engine, manual 6-speed transmission, 7 seats, and the Comfort trim level. It currently has 220,000 km on the odometer.

I bought it about 5 years ago. A software update was already performed before the purchase, and a new AGR valve was installed as part of that process.

Two years ago, it started with a crack in the downpipe of the DPF. The error message was "AdBlue effectiveness too low." When replacing it (with an aftermarket DPF), it was discovered that the SCR catalyst was also cracked/brittle on the inside. Okay, I swapped the JMJ scr Kat (catalytic converter) for a new one and also replaced the NOx sensor (including accessories).

Things went well until around July of this year. Another crack in the drainpipe.

After the repair, the "SCR efficiency too low" error reappeared. So, I replaced the JMJ SCR catalytic converter again. After the replacement (and also a new VW NOx sensor), the error reappeared after about 300 km (even though the error had previously disappeared). (Is the catalytic converter failing so quickly, or is it just cheap?). Regarding VW: a new catalytic converter is required because it's not "original," and a software update from 9980 to 9982 was performed. The error reappeared after the SCR efficiency test (which had previously passed with the old parts). New ORC (Organic Rankine Cycle) unit not available - as of today.

After a short time, the errors reappeared. I bought more original (allegedly refurbished) parts, which were internally intact. The errors disappeared after a short drive. So far, there's no countdown, but the "SCR system working" message is already showing again, initially sporadically, but now constantly since yesterday. No countdown. Injector: I've already replaced it three times in the past two years – surely not all of them can be broken. Tested in the basement with 5 bar, three streams of fuel are coming out, and it's been cleaned multiple times. NOX sensor: Original VW part, purchased about 4 months ago. Sure, here's the translation:

"Please ensure there are no errors."

The system pressure for the working medium is 5 bar, and the pump was replaced two years ago.

What I don't understand is that every time I replace the KAT (likely a component or device) with a "new" one, the error appears again after a short time. For example, when the countdown was active, it removed the faulty component, but the error reappeared. How could that possibly work together?

AGR tested with OBD, no errors found.
AdBlue tested with a refractometer and found to be within the specified range.

Another possibility is the fuel level indicator. During the two years when everything was working, I once drove the SCR tank completely empty. There was no warning message. It always showed 80%. But I'm not going to exchange it (due to) an unfounded suspicion; I've already spent so much money.

I'm driving slowly, just below or at 80-90 km/h, to keep the SCR system within its operating temperature range until I can pinpoint the problem. My hypothesis is that if I drive faster, it will reactivate the counter.

My thesis: If the two cats initially contributed to troubleshooting, why should they be broken? It's more likely that the cats are being "deactivated" and not receiving any further instructions. However, a measurement test revealed that the nozzle was active to a degree of up to 15%.

What else can I measure to get to the root of the problem?

Thank you. Best regards, Thorsten.

Hi Thorsten,
It's always helpful to include an Autoscan report with the error description. This allows you to see more details about the engine and the errors. Is the 7N a Sharan II?
A very simple question: Is the filling and venting system for the AdBlue tank working properly? The AdBlue error seems to disappear whenever work has been done on the system.
How many kilometers did you drive on a full tank?
hg
Herbert.

Edit: For those interested, the troubleshooting information was already available here.
https://tx-board.de/threads/scr-expertenfrage.157963/
and here.
https://www.motor-talk.de/forum/ad-blue-was-kann-es-noch-sein-t7532965.html

Just a gut feeling – could it be that the damaged exhaust system and the SCR error are not related? Is AdBlue injected before or after the exhaust pipe?

Hello and thank you for the reply.
It's a SGA II (actually, it's the third generation, so why is it called the SGA II?), manufactured in December 2010, with a Cffb engine (0603, ATV).

Both links are from me; I'm currently trying to consult with all the experts to see where else I could look.
I would like to understand which errors or events trigger the countdown. Based on what I've read, in the MSG, the SCR efficiency is counted 20 times before the countdown is activated.

Ventilation... hmm, if that's the case, the system pressure shouldn't remain stable; it should drop, right?

I last refilled the AdBlue at the BK gas station. The refractometer reads 32.4%.

Attached is a log file from a highway trip, it's a bit old. Here, you can clearly see that everything seems to be working properly.

Hello, here's the summary (from back then).

Date: 2023-09-03 18:35

FIN: WVWZZZ7NZBV021413
Vehicle: Volkswagen Sharan
Year: 2011
Body type: MPV.
Engine: CFFB
Mileage: 219,360 KM

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
01 Motor electronics.

System description: R4 2.0l TDI.
Software number: 03L906018HH
Software version: 9982.
Hardware number: 03L907309Q.
Hardware version: H24.
ODX Name: EV_ECM20TDI01103L906018HH
ODX Version: 003017
Long encoding: 0019003A043401080000

Error codes:
P20EE00 - NOx Catalyst Efficiency Below Threshold, Bank 1.
static
Mileage: 219,364 km
Priority: 2
Error frequency counter: 1
Counter for lost items: 255.
Motor speed: 1500.00 rpm.
Normalized load value: 21.2 %
Vehicle speed: 0 km/h
Coolant temperature: 73 °C
Intake air temperature: 49 °C
Ambient air pressure: 950 mbar.
Voltage at terminal 30: 14,500 V.
Dynamic environmental data: 20962813C3006414DF000014E2032715FF000015271656


"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
03 Brake electronics.

System Description: J104 C3 450M VD23
Software number: 7N0614109L.
Software Version: 0008
Hardware number: 7N0614109L
Hardware version: K03.
Serial number: 00000003504257.
Encoding: 0019223

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
04 Steering angle sensor.


Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
08 Climate control/heating electronics.

System Description: Clima-Sharan.
Software number: 5K0907044G.
Software version: 0104.
Hardware number: 5K0907044G.
Hardware version: H11.
ODX Name: EV_ClimatronicSharan
ODX Version: A01005
Long code: 0000000109

Subsystems:
System Description: KBT-H
Software number: 7N0907049B.
Software Version: 0101
Hardware version: 003.
Serial number: 20101201000000010234

Error codes:
B10AF04 - Air quality sensor failure.
static
Mileage: 219,057 km
Priority: 3
Error frequency counter: 51
Lost Count: 35


"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
09 Central electronic electrical system.

System Description: BCM PQ35 M
Software number: 5K0937086J.
Software Version: 0046
Hardware number: 5K0937086J
Hardware version: 011.
Long encoding: 40180A3B81251AC0400800C0540081E443511308426D25626480C70000C1

Subsystems:
System Description: WWS 110910
Software number: 7N1955119A.
Software Version: 0032
Hardware version: 31.
Serial number: 110913183853
Long code: 000D9D

System Description: RLHS
Software number: 5Q0955547B
Software Version: 0107
Hardware version: 052
Serial number: SAY18M08D29H21M01S35
Long code: 0380DD

Error codes:
03384 - Windshield washer nozzle heater: Open circuit/short circuit to positive.
static
Priority: 4
Frequency counter: 15
Driving cycle: 35
Mileage: 219,057 km


"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
10 Parking Assist 2

System Description: PARKHILFE PLA
Software number: 3AA919475D.
Software Version: 0007
Hardware number: 3AA919475A.
Hardware version: H04
Serial number: 20431033500823.
ODX Name: EV_EPHVA2C0000000000
ODX Version: 001006
Long code: 11820D

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
15 airbags.

System Description: VW10Airbag01X
Software number: 7N0959655B.
Software Version: 0013
Hardware number: 7N0959655B.
Hardware version: H07.
Serial number: 003GFPQM2TNW
ODX Name: EV_AirbaVW10TS6VW428
ODX Version: A01002
Long code: 003158

Subsystems:
System Description: S.Sens.Fahr.V (This likely refers to a system related to sensors in vehicles.)
Software Number: ---
Software Version: ---
Hardware version: ---
Serial number: 3493ETS6049CE1E139D4
Long code: 000000

System Description: Front Passenger Side Sensor.
Software Number: ---
Software Version: ---
Hardware version: ---
Serial number: 3503ETS60F14F1A13DDZ
Long code: 000000

System Description: S.Sens. Fahr.H (likely an abbreviation, meaning something like "System Description: Sensor, Vehicle, Function H")
Software Number: ---
Software Version: ---
Hardware version: ---
Serial number: 3513ETS6060821E139DH
Long code: 000000

System Description: Front Passenger Side Sensor.
Software Number: ---
Software Version: ---
Hardware version: ---
Serial number: 3523ETS60BFFD1C13DDF
Long code: 000000

System Description: F.Sens. Vehicle.
Software Number: ---
Software Version: ---
Hardware version: ---
Serial number: 35540TS602D583A13DDM
Long code: 000000

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
16 Steering column electronics.

System Description: STEERING MODULE.
Software number: 5K0953501BB
Software Version: 0136
Hardware number: 5K0953569H.
Hardware version: 009.
Serial number: 20101210200045
ODX Name: EV_VW360SteerWheelUDS
ODX Version: A03004
Long code: 5180240000

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
17. Terminal block insert.

System Description: KOMBI
Software number: 7N0920870A.
Software Version: 0420
Hardware number: 7N0920870A
Hardware version: H20.
Serial number: 00000000000000
ODX Name: EV_Kombi_UDS_VDD_RM09
ODX Version: A04086
Long code: 140B00

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
18 Auxiliary/Parking Heater

System Description: Portable Heater - Model 051.
Software number: 7N0963271A.
Software version: 2630.
Serial number: 09022126000000
Encoding: 0001042

Error codes:
02245 - No signal/communication from the wireless remote control.
static
Priority: 6
Frequency counter: 6
Driving cycle: 34
Mileage: 219,057 km


"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
19. Diagnostic interface for data bus.

System Description: J533 Gateway.
Software number: 7N0907530D.
Software Version: 0614
Hardware number: 1K0907951
Hardware version: H35
Serial number: 261110F2003084.
Long code: 468002

Error codes:
01207 - Control unit for auxiliary heater - No signal/communication.
sporadically
Priority: 2
Frequency counter: 4
Driving cycle: 71
Mileage: 219,118 km
01300 - Navigation control unit with CD drive - No signal/communication.
sporadically
Priority: 2
Frequency counter: 49
Driving cycle: 75
Mileage: 219,057 km
01044 - Control unit incorrectly coded.
sporadically
Priority: 1
Frequency counter: 51
Driving cycle: 255
Mileage: 219,057 km


"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
25 Anti-theft device.

System Description: IMMO
Software number: 5K0953234
Software Version: 0420
Hardware number: 5K0953234
Hardware version: H20.
ODX Name: EV_Immo_UDS_VDD_RM09
ODX Version: A03008
Long code: 000000

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
37 Navigation.


Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
42 Door electronics, driver's side.

System Description: TSG FA
Software number: 7N0959793D.
Software version: 0400
Hardware number: 7N0959793.
Hardware version: H04
Serial number: 0000110543873.
Long encoding: 011006208000411011

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
44 Steering assist.

System Description: J500__APA-BS, Size 323.
Software number: 5N1909144L.
Software Version: 0802
Hardware number: 5N1909148G *
Hardware version: H03.
Serial number: 00103290297201.
Encoding: 0000258

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
46 Central Module for Comfort System.


Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
4F Central Electronics for Power Distribution 2

System Description: EZE_2
Software number: 7N0907532.
Software Version: 0614
Hardware number: 1K0907951
Hardware version: H35
Serial number: 261110F2003084.
Long encoding: 050B0500

Subsystems:
System Description: J245EE20SKB13
Software number: 8R0959591A
Software Version: 0220
Hardware version: H02.
Serial number: 0123456789ABCDEFGHIJ

System Description: J394EE20SKB13
Software number: 8R0959591A
Software Version: 0220
Hardware version: H02.
Serial number: 0123456789ABCDEFGHIJ

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
52 Door electronics, passenger side.

System Description: TSG BF
Software number: 7N0959792D.
Software version: 0400
Hardware number: 7N0959792.
Hardware version: H04
Serial number: 0000109944693.
Long encoding: 011006208000411011

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
53 Parking brake.

System Description: J540 EPB4, VW-53083.
Software number: 3AA907801D.
Software Version: 0006
Hardware number: 3AA907801D
Serial number: 00000000130225.
Encoding: 0024067

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
56 Radio.

System Description: Radio RCD310.
Software number: 5M0035186AA
Software version: 0049.
Hardware number: 5M0035186AA.
Hardware version: 016
Serial number: VWZ1Z2K8576937.
Long encoding: 0500040004

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
61. Battery regulation.

System Description: Battery Management System.
Software number: 7N0907534.
Software Version: 0614
Hardware number: 1K0907951
Hardware version: H35
Serial number: 261110F2003084.
Long encoding: 030B785A

Subsystems:
System Description: J367-BDM
Software number: 1K0915181F
Software Version: 0150
Hardware version: H07
Serial number: 00000000009370222306

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
62 Door electronics, rear left.

System Description: TSG HL
Software number: 7N0959794E.
Software version: 0400
Hardware number: 7N0959795A.
Hardware version: H03.
Serial number: 0000110533059.
Long encoding: 010004200000411001

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
69 Follower function.

System Description: Trailer.
Software number: 7N0907383.
Software Version: 0101
Hardware number: 7N0907383.
Hardware version: H07.
Serial number: 00000138886085.
Long encoding: 410C040001000000

Error codes:
No error codes found.

"Die Sonne scheint hell, und die Vögel zwitschern fröhlich. Es ist ein perfekter Tag für einen Spaziergang im Park."
72 Door electronics, right rear.

System Description: TSG HR
Software number: 7N0959794E.
Software version: 0400
Hardware number: 7N0959795A.
Hardware version: H03.
Serial number: 0000110533226.
Long encoding: 010004200000411001

Error codes:
No error codes found.

Hello,

Quote:

Another crack in the pipe.

How is that possible? The engine is tuned, and it's causing the exhaust system to overheat? Where did the crack come from? Could it be because something else is wrong, and the SCR issue is a secondary problem? Coolant leak, engine smoking, and excessively high exhaust temperature?
Let me check that out.

Of course, the engine control unit (ECU) software itself can also be the source of the problem.
If the AGR-Off function was programmed, that could also be the cause.

Best regards, Rainer.

Hello,

I'd also like to know how to do that. I suspect that the rubber in the torque strut might be soft after 220,000 km.

The inspection revealed minor imperfections, but no major defects or anything similar. I'll do that soon.
Currently, a new DPF (Diesel Particulate Filter) is installed, so the system is sealed.
Follow-up errors are therefore less likely.

Every time I install a "new" catalytic converter, it clears the active error code while the car is running, but the error code reappears. That's the strange thing.

So, assuming we're starting with a (seemingly) intact catalyst, the only remaining possibilities are either the AdBlue itself or the AdBlue supply system. The AdBlue concentration in the tank, as measured by refractometer, is 32.4%. New canister from the hardware store, 32.5 liters, with the same refractometer.
Since the pressure is always at 5 bar (see measurement record), the only remaining possibility is the injector. I've cleaned two of them, and three injectors are spraying. Alternatively, it could be the engine control unit (ECU) or the software. However, it doesn't make sense that the problem would disappear completely after replacing the catalytic converter. That's why it's so tricky.

My impression is that the (memory) cat is running out of ammonia and then stops processing anything further. I'm looking for a method to narrow it down/measure it.

Or it could be the AGR, even though it's not showing any error codes.
Question: If I currently run the SCR efficiency test without a countdown, and it fails, will it automatically trigger the countdown?

Thank you. Best regards, Thorsten.

Hi,
The "downpipe" or exhaust pipe seems to be prone to cracking. VW specifies a special transport securing device for the decoupling element during removal and installation. If it's then installed under tension...
The adjustment was made after the exchange.
Is the mixer in the exhaust pipe, before the catalytic converter, still present?

AGR problems can be identified by comparing the amount of air being drawn into the engine with the AGR rate.
hg
Herbert.

The DPF arrived without any transport protection, which is understandable since it's an aftermarket DPF.
Are you tense? No, it's installed at the top first, then the bracket is attached, and finally the catalytic converter is put on.

Yes, the mixer and the metal sheets are already installed; I checked them beforehand.

AGR rate to air mass as a quotient, or where can I find more detailed information about this?

Is there a logged driving profile available somewhere where I can see the amount of NOx emissions under different loads for comparison? "Where should the area be located?"

Thank you. Best regards, Thorsten.

Hi,

Pannwitz wrote:

The DPF arrived without any transport securing, which is understandable since it's an aftermarket DPF. Are you tense? No, it will be mounted at the top first, then the bracket will be attached, and then the catalytic converter.

However, we already agree that cracks are caused by overload or quality defects, right?

Quote:

Yes, the mixer and the metal sheets are installed; I checked them beforehand.

Marked as complete.

Quote:

AGR rate to air mass as a quotient, or where can I read more about this?

This refers to a full-load operation where the boost pressure and maximum air mass are determined with zero AGR, and the measurement of exhaust gas recirculation, boost pressure, and air mass (the latter for plausibility) during partial load.

And then, again, the question about adjustments after replacing the DPF and sensors?
hg
Herbert.

[quote="Herbert"]Hi,

Pannwitz wrote:

The DPF arrived without any transport securing, which is understandable since it's an aftermarket DPF. Are you tense? No, it will be mounted at the top first, then the bracket will be attached, and then the catalytic converter.

However, we already agree that cracks are caused by overload or quality defects, right?

Sure, that's why the idea of a torque strut exists, or... Rubber. (Tipping moment)

Quote:

Yes, the mixer and the metal sheets are installed; I checked them beforehand.

Marked as complete.

Quote:

AGR rate to air mass as a quotient, or where can I read more about this?

This refers to a full-load operation where the boost pressure and maximum air mass are determined with zero AGR, and the measurement of exhaust gas recirculation, boost pressure, and air mass (the latter for plausibility) during partial load.

Are those the 15 seconds of acceleration he needs for the measurement? Would an AGR error be registered in the vehicle's diagnostic system (n.i.o.)?

And then, again, the question about adjustments after replacing the DPF and sensors?

After replacing the DPF and the 2nd, new JMJ catalytic converter, and with no other interventions, a constant highway drive cleared the error. Before that, I had probably run the efficiency test 4-5 times (with the 1st catalytic converter). I also reset the fuel gauge a couple of times (after filling it up, of course).
What I hadn't done yet was reset the fuel sensor and then run the SCR efficiency test. Apparently, it should make a difference.
Currently, the error is not active. I'm not driving as far to work, and I'm only driving 90-100 km/h on the highway (SCR max 200°C). I check the MSG once a week, and so far it's been green. However, the Readiness status for the exhaust system is at 0 (after clearing the error code "SCR effectiveness too low, static").

Thank you. Best regards, Thorsten.

Hi,
Torque strut and rubber mounting are constructive measures, but they do not protect against installation errors and improperly tensioned installation.
When replacing a particulate filter, the ash mass and differential pressure must be adjusted. When replacing the SCR catalyst and/or the NOx sensor, an adjustment is likely also required.
My impression, and I don't want to offend you, is that you're not aware of these things. Is a repair manual available?
It's quite possible that if the ash mass isn't adjusted after a DPF replacement, the DPF itself can accumulate soot, and this may not be detected because the high pressure difference is attributed to the ash. And then, when overloaded, it can trigger a forced regeneration. DPF and SCR catalytic converters, farewell.
Your response to my suggestion for determining the maximum air mass and EGR rates is just as strange. Why don't you simply record data (engine speed, fuel injection quantity, air mass, boost pressure, EGR rate, differential pressure, and possibly soot levels). Step 1: Autobahn, 5th gear. Throttle, full throttle from 1500 RPM to 4000 RPM.
hg
Herbert.

Herbert wrote:

Hi, Torque strut and rubber mounting are constructive measures, but they do not protect against installation errors and improperly tensioned installation.

I had already explained that it was done in that order and how... I think that's correct.

When replacing a particulate filter, the ash mass and differential pressure must be adjusted. When replacing the SCR catalyst and/or the NOx sensor, an adjustment is likely also required.

Assumption or knowledge? SCR and the probe were replaced. If calibration was important, why did he delete the error message afterward?

My impression, and I don't want to offend you, is that you're not aware of these things. Is a repair manual available?

My neighbor works at... and helped me.

It's quite possible that if the ash mass isn't adjusted after a DPF replacement, the DPF itself can accumulate soot, and this may not be detected because the high pressure difference is attributed to the ash. And then, when overloaded, it can trigger a forced regeneration. DPF and SCR catalytic converters, farewell.

Can...? So, a guess. Is it going to catch fire? What's catching fire, where, and how? I'm familiar with regeneration; the system must be able to tolerate it due to its design and function. Especially after the software update, where the lambda value was increased to reduce NOx, which leads to more soot and more frequent regenerations, ultimately shortening the lifespan because it wasn't "originally" tested. I think that's well-known.

Your response to my suggestion for determining the maximum air mass and EGR rates is just as strange. Why don't you simply record data (engine speed, fuel injection quantity, air mass, boost pressure, EGR rate, differential pressure, and possibly soot levels). Step 1: Autobahn, 5th gear. Throttle, full throttle from 1500 RPM to 4000 RPM.

I've already attached the recording above, but AGR (Automatic Gear Recognition) isn't included yet because there are no errors detected. If I were to force it, it might end up in the counter, which wouldn't be helpful. I'm trying to prevent that exact thing from happening again. So, without trying anything further, I want to diagnose the problem more thoroughly.

And DPF (actually) isn't the main topic here; I'm more concerned with the efficiency issue. Of course, if there's a connection, I can see it, but I haven't seen it yet.
But thank you for the tips.

Hi,

Quote:

Assumption or knowledge?

The latter.
I suspect that I'm beating a dead horse here. You just want information about my personal thought processes, but you're not looking for real advice. I'm getting off here.
hg
Herbert.

Hello,

I would first determine the values for ash content and differential pressure after regeneration.

Where, how, what, and comparison:
Okay, I'm ready. Please provide the German text you want me to translate.
Okay, I'm ready. Please provide the German text you want me to translate.

Then I would check if the EGR system is working correctly.

Warning: AGR pipes can sometimes rupture, as happened with my T6. Depending on the pressure conditions, air can enter and exhaust gases can exit, which can cause everything to get mixed up.

Then I would check if the actual air mass values are plausible. Ideally, I would record data during idle and a full-throttle cycle up to 4000 rpm, along with engine speed, fuel injection volume, and actual intake manifold pressure.

What about the note regarding SCR tank ventilation that was already mentioned in the topic?

Best regards, Rainer.

And a log file with a megabyte of data... please.

Okay, I'm ready. Please provide the German text you want me to translate.

Hello and thank you for the additional responses.
I mentioned the AGR because someone in another forum had similar problems with their Alhambra, and the issue only disappeared after replacing the AGR, even though it wasn't showing up as an error.

Is there anyone in the Munich area who has this software and knows how to record with it?
My concern is that during the attempts, the errors might reappear, and I could end up in a never-ending cycle of costs.

After 222,000 km, I'm starting to question whether it's worth it. After installing (including each series) the third DPF and the fourth SCR catalyst... the attempts are futile. Time to give up.

Currently, I can prevent the SCR system from triggering at speeds of 90-100 km/h by maintaining a temperature of approximately 200-215°C. Sure, it's not a perfect solution, but it might get me through the winter. Besides, the vehicle inspection (HU) is due in March anyway.

Most workshops will probably just swap out parts, but that will be too expensive for me because almost everything is already worn out. But everyone has to try it again; if it doesn't work, it's probably something else, and they can keep swapping parts.

To be honest, I'd also like to take a break from this topic.

Therefore, the question arises about the efficiency test, which is also conducted by VW. Shouldn't the learning values, etc., be reset in conjunction with this? And if the result is negative, should I re-enable the counter?

Thank you for the AGR tips. Best regards, Thorsten.