DPF Full: Audi A8 3.0 V6 - High Pressure

Good day, fellow diesel mechanics.

I've solved this problem, but unfortunately I still have some questions for you, and I hope you can help me.
My father has an Audi A8 4H, first registered in February 2011, with engine code CDTA (V6 TDI CR).
In June 2017, I installed a new differential pressure sensor for the DPF in the car because the old one was reporting an electrical fault. I only replaced the sensor and cleared the error memory.
Now, 3 months later, I received the car with the following problem:

Friday, September 22, 2017, 9:52:59 PM (07:23:6)
VCDS - A VAG/VAS emulator based on Windows, running on Windows 7 x86.
VCDS version: RKS 17.1.3.0
Data as of: 20170224 DS267.4
http://shop.dieselschrauber.de

Address 01: Engine Control Module
Label file: DRV\059-907-401-V2.CLB
Control unit part number: 4H0 907 401. Hardware: 4G0 907 401.
Component and/or version: 3.0 TDI EDC17 H37 0004.
Encoding: 4A2A401A056601020000
Company number: WSC 02311 785 00200
ASAM Dataset: EV_ECM30TDI0114H0907401 001010 (AU64)
ROD: EV_ECM30TDI0114H0907401.rod
VCID: 61C21BE07055EE4986-8034
Two error codes found:

5188 - Diesel particulate filter - Excessive soot load.
P2463 00 [167] - -
Warning light ON - unconfirmed - checked since last reset.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1.
Mileage: 121986 km
Date: 2017.09.22
Time: 21:51:04

Motor speed: 758.50 rpm.
Normalized load value: 27.8%
Vehicle speed: 0 km/h
Coolant temperature: 79 °C
Intake air temperature: 37 °C.
Atmospheric pressure: 990 millibars.
Voltage at terminal 30: 14,260 V.
Lost learning counter via OBD: 40.
P Flt Ld fac Ash Cor: 0.8950
Differential pressure of the particulate filter: 98 hPa.
Exh t Adap T Oxi Cat Ds: 224.0 °C
Exhaust Adapter Temperature (TP) Flight Data: 227.9 °C
Exhaust gas volumetric flow rate in the particulate filter: 63.8 m³/h.
Current operating mode_2-bit: 0: 0
Current operating mode: 2 bits, 16:16.
Current operating mode (2 bits): 24: 0.
Current operating mode: 2 bits, value: 8 (binary 0000).

5189 - Particle filter, bank 1.
P2002 00 [039] - Malfunction.
Unconfirmed - checked since last deletion.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1.
Mileage: 121986 km
Date: 2017.09.22
Time: 21:51:04

Motor speed: 758.50 rpm.
Normalized load value: 27.8%
Vehicle speed: 0 km/h
Coolant temperature: 79 °C
Intake air temperature: 37 °C.
Atmospheric pressure: 990 millibars.
Voltage at terminal 30: 14,260 V.
Lost learning counter via OBD: 40.
Outside temperature: 14.5 °C
Particulate filter: Pressure difference offset: 22 hPa.
Particle filter: Soot mass measured: 41.68 g.
Particulate filter: Calculated soot mass: 42.45 g.
Particle filter: Kilometers since last regeneration: 486765 km.
Particle filter field regeneration: Abort condition bit 0: 0.
Particle filter field regeneration: Abort condition bit 8: 0.


After that, I drove the vehicle for about 30 km and checked the calculated soot mass during the trip. Even after driving 30 km, the actual soot mass decreased to approximately 7 grams, while the "calculated soot mass" increased. The whole process looked like this:

Address 01: Engine Control Module
Label file: DRV\059-907-401-V2.CLB
Control unit part number: 4H0 907 401. Hardware: 4G0 907 401.
Component and/or version: 3.0 TDI EDC17 H37 0004.
Encoding: 4A2A401A056601020000
Company number: WSC 02311 785 00200
ASAM Dataset: EV_ECM30TDI0114H0907401 001010 (AU64)
ROD: EV_ECM30TDI0114H0907401.rod
VCID: 61C21BE07055EE4986-8034
Two error codes found:

5188 - Diesel particulate filter - Excessive soot load.
P2463 00 [167] - -
Warning light ON - unconfirmed - checked since last reset.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1.
Mileage: 122,016 km
Date: 2017.09.22
Time: 22:16:24

Motor speed: 751.00 rpm.
Normalized load value: 35.3%
Vehicle speed: 0 km/h
Coolant temperature: 80 °C.
Intake air temperature: 17 °C
Ambient air pressure: 1000 millibars.
Voltage at terminal 30: 14.260 V.
Lost learning counter via OBD: 40.
P Flt Ld fac Ash Cor: 0.8950
Differential pressure of the particulate filter: 115 hPa.
Exh t Adap T Oxi Cat Ds: 226.0 °C
Exhaust Adapter Temperature (TP) Flight Data: 282.5 °C
Exhaust gas volumetric flow rate in the particulate filter: 69.7 m³/h.
Current operating mode_2-bit: 0: 0
Current operating mode: 2 bits, 16:16.
Current operating mode (2 bits): 24: 0.
Current operating mode: 2 bits, value: 8 (binary 0000).

5189 - Particle filter, bank 1.
P2002 00 [039] - Malfunction.
Unconfirmed - checked since last deletion.
Environmental conditions:
Error status: 00000001
Error priority: 2
Error frequency: 1.
Mileage: 122,016 km
Date: 2017.09.22
Time: 22:16:24

Motor speed: 751.00 rpm.
Normalized load value: 35.3%
Vehicle speed: 0 km/h
Coolant temperature: 80 °C.
Intake air temperature: 17 °C
Ambient air pressure: 1000 millibars.
Voltage at terminal 30: 14.260 V.
Lost learning counter via OBD: 40.
Outdoor temperature: 14.0 °C
Particulate filter: Pressure difference offset: 22 hPa.
Particle filter: Soot mass measured: 7.42 g.
Particulate filter: Calculated soot mass: 43.70 g.
Particle filter: Kilometers since last regeneration: 516512 km.
Particle filter field regeneration: Abort condition bit 0: 0.
Particle filter field regeneration: Abort condition bit 8: 0.

So far, so good, or not. A service regeneration of the DPF was interrupted after a few seconds for "safety reasons."
Mir kam der fast feststehende Differenzdruck von 98 hPa (schwankte in der freien Beschleunigung um max. 10 hPa) sehr komisch vor. Ich wechselte daraufhin nochmals den Differenzdrucksensor und habe dem Motorsteuergerät erzählt, dass ich einen neuen eingebaut habe (Über Anpassung 10 im MStG). Der Wert war danach bei ca. 30hPa im Leerlauf. Daraufhin habe ich eine Serviceregeneration durchgeführt, was auch wunderbar funktionierte. Sowohl die „gemessene“ und auch die „berechnete Russmasse“ gingen dabei auf einen Wert von 0,?? Gramm.
After that, I cleared the error codes, and the car is running perfectly again.

Now I have a few questions about this problem.

1. Should I have had to calibrate the new differential pressure sensor in June? Or was that possibly the reason why it stopped regenerating during driving? If not, then there must still be another underlying issue.
2. Have you ever experienced a situation where a new differential pressure sensor failed so soon after being installed?
3. Where does the engine control unit get the "calculated soot mass" value from?

As a note: My father is a long-distance driver and had just returned from Dortmund (about 125 miles) shortly before the error occurred. The driving profile is normal; no constant full throttle, etc.

Thank you in advance for your answers..After that, I cleared the error codes, and the car is running perfectly again.Now I have a few questions about this issue.1. Did I need to calibrate the new differential pressure sensor in June, or was that possibly the cause of the problem?"Did it stop regenerating while driving? If not, then there must still be another problem."available.Have you ever experienced the phenomenon where a new differential pressure sensor fails again after such a short period of time?Where does the engine control unit obtain the "calculated roughness"?My dad is a long-haul truck driver and had just returned from Dortmund shortly before the error occurred (approximately 200 km). The driving profile was normal; he wasn't constantly accelerating or driving at full speed.I thank you in advance for your answers.

Hi,

It's always a good idea to recalibrate the system after replacing the differential pressure sensor, as this allows the engine control unit (ECU) to immediately learn what "zero differential pressure" is.
Differential pressure sensors from previous years often only lasted for 50,000 to 100,000 km, but that shouldn't be a problem anymore. Of course, that doesn't mean you can't have bad luck.
The calculated soot mass is determined from the differential pressure measured under various load conditions. The fuller the DPF (with ash and soot), and the higher the air mass flow and engine speed, the higher the differential pressure.

Generally, you should check if there are any conditions that prevent the DPF from regenerating.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

Best regards, Rainer.

Thank you very much, Rainer, for the quick and competent response .

Differential pressure sensors should only be replaced with genuine Bosch parts. I have had consistently bad experiences with sensors from brands like Metzger or those purchased from online marketplaces.