A8 3.3 TDI | Posts 16+

Exhaust gas recirculation (EGR) is OK. Values are:

MWB 003.2 = active.
MWB 003.3 = 164.5 mg/dose; multiple samples showed a highest value of 221.5 mg/dose.
MWB 003.4 = 0.0%

MWB 003.2 = inactive.
MWB 003.3 = 399.1 mg/vial; the value is always between 371.5 - 399.1 mg/vial.
MWB 003.4 = 100.2%

I don't know what else to do.

Then we move on to checking.

Sebastian@OpenOBD wrote:

If the value for "AGR not active" is within the expected range, then proceed as follows: Check the actual value when "AGR active" is enabled. "If the target value is now reached, check the boost pressure control." < If the target value is still not reached = replace the EGR valve(s)

Therefore, check the turbocharger pressure control system and use the default settings in module WB 033 for this purpose.

Since the two chargers are controlled differently, one must always have a value in the range of 550-800 mg/H, while the other must be in the range of 100-300 mg/H.

Hi,

I'd like to chime in on this thread a bit, as I'm currently working on solving a very similar problem.

Engine code: also AKF, 3.3L common rail.

Data version: D04 instead of D03, which means the measurement data blocks should be identical to those from Opelfreak.

Error memory: also.
17567 - Air mass sensor signal: Implausible ratio between air mass sensor 1 and air mass sensor 2.
P1159 - 35-10 - - - Intermittent.
The error reappears immediately after being cleared.

Measurement block 25.4 (LMM2, G246) is consistently significantly lower than 25.3 (LMM1, G70). This also applies to higher speeds.

The symptoms of a faulty EGR valve and a defective mass airflow sensor (MAF) are likely quite similar (okay, the MAF should show a more significant drop in readings, while the EGR might have a broader impact, but I'm not entirely sure about that). Therefore, I want to first rule out the MAF sensor, G246 , and replace it.

Okay, I have a problem now: Both LMMs (likely referring to Lambda Oxygen Sensors) have the same part number, and I don't know which one is the right side and which one is the left side (from the driver's perspective). Until now, I could only tell them apart by the different wire colors. Does anyone know which program I need to use to find out?

Thank you and best regards.
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

Unfortunately, I haven't seen the engine yet, but isn't it irrelevant which motor goes on which side?

Simply swap them and see what happens. If the values change along with the swap, then it's likely the mass airflow sensor (MAF). If the values don't change, then it's probably the exhaust gas recirculation (EGR) valve.

Or have I made a mistake in my thinking, or do I not understand you correctly?

Best regards!

Hi R.M.,

Yes, you're basically right. However, it's not quite as straightforward with that engine as it is with our cute little R4 TDIs. With the eight-cylinder engine, a lot of things have to be removed to replace the mass airflow sensor (MAF), because the MAFs are located behind the engine (between the engine and the firewall), and there isn't much space there.

I would therefore like to directly replace the LMM2 with a new one and not exchange it multiple times. However, I need to know which of the LMM2 models is the G246.

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

I understand. However, you would still need a mass airflow sensor (MAF) "just in case," even though the problem might not be related to it. Also, you'll have to disassemble quite a bit just to replace that one part.

Best regards!

The air mass meter 2 -G246- is on the right side. When you are standing in front of the car.

Thanks, Mulle!

Gefährlich... Rechts von vor dem Auto stehend gesehen betrachtet. Also links in der Auto-Fachsprache. Einigen wir uns auf Fahrerseite, damit wir wirklich von der gleichen Richtung sprechen?

Can you tell me which program it might be in? I couldn't find it in the common programs. (You can also send me a private message if it's not appropriate to discuss here.)

Thank you and best regards.
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

Let's agree on the driver's side so that we are sure .


We agree .

If the engines are from 2000 and the cylinder heads are essentially the same as those used in the V6 TDI models, then they should also be affected by the issues related to the water pump and hydraulic components. Differences between the two engine banks are certainly possible and don't necessarily have to be caused by a faulty mass airflow sensor.

Here's a brief explanation from me: It was the G246, specifically the LMM2 sensor on the driver's side.

Although the LMM2 still reports a significantly lower air mass than the LMM1 at idle, they equalize around 1500 RPM, and after that, the LMM1 takes the lead.

I can't explain why the new LMM2 is reporting significantly lower values in the lower range. Both EGR valves are sealing properly, and I haven't been able to detect any leaks between the LMM and the turbocharger either.

If anyone else is experiencing this: After hours of tinkering, I'm now regretting not replacing the MAP sensor (LMM1) at the same time. It's also a wear item and reports significantly less mass in the higher RPM range.

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

If anyone is still working on it...
Inside the wheel well, there is a vacuum chamber with a vacuum line connected to it.
At the transition point between the pipe and the container, there is a plastic piece installed that is prone to tearing or breaking.

Perhaps it's worth checking if there are any leaks on the vacuum side that cannot be ruled out.

Now, the above-described engine (3.3 common rail, biturbo) is experiencing a problem with oscillating acceleration, occurring approximately every 3 seconds within the 3000 RPM range.

Since the vehicle has two turbochargers, I would like to see the individual boost pressures and their trends. However, I don't know which data block contains this information.

Does anyone have a suitable label file for the part number 4D0 907 409 A?

Of course, I'll also check the vacuum container in the wheel arch, as that could also be the problem.

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

Do you have the latest version of VAG-COM? If so, please contact me directly.

Hello Sebastian,

I have already visited your page and read with interest about the possibility of creating custom designs starting from version 505.1.

However, I'm using a very old, custom-built optocoupler circuit, so I can't use the 505.1.

I would still appreciate any help.

Best regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.

guste100 wrote:

Since the vehicle has two turbochargers, I would like to see the individual boost pressures and their trends. However, I don't know which data block contains this information.

Just to clarify this again, in case anyone experiences fluctuating boost pressures at the air intake manifold: there are not two separate boost pressures, as the charge air path connects directly to the common air/water intercooler after the turbochargers. Therefore, there is only one overall boost pressure.

The turbochargers are simply controlled together. The only difference in how the chargers are activated (up to 5%) is determined by the amount of air flowing through the charger-specific mass airflow sensors (MAF sensors). Therefore, my suggestion: always replace both MAF sensors at the same time. If one MAF sensor is weaker than the other, the corresponding turbocharger will be consistently driven more aggressively.

Regards,
Sure.

Here is the translation of the text from German to English:

"Guste" means "gust" in English. It refers to a sudden and strong gust of wind.