leistungverlust A6 2.5 | Posts 16+

Hi,

The rest is okay, but where can I find the intake air temperature reading in VAGcom?

Regards,

Richard.

Are you looking here: http://www.dieselschrauber.de/Solldaten_Main.html?

You can also check your other measurements at the same time.

Unfortunately, the intake air temperature is not being displayed in degrees Celsius.

Where did you actually get the "new" LLM that you installed?

How many pins does your MAF sensor connector have, and what colors are they?
It might be possible to test a replacement mass airflow sensor (MAF) using a resistor. I don't know if your engine control unit (ECU) will detect this.
However, it would be worth trying, because if your car behaves normally with the fake Mass Air Flow (MAF) sensor above 3000 min{-1} <sup>, you can assume that the MAF sensor is defective.

Best regards, Rainer.</sup>

Hello Rainer,

I'll check the intake air temperature today.
One of the LMMs (likely referring to a mass airflow sensor) came from a Passat V6 TDI manufactured in 1999, and that Passat ran well with it.
I also have a different LMM (mass airflow sensor) installed, one from a Passat 1.9 TDI, and the engine control unit recognized it as incorrect.
My LMM connector has 5 pins and the color is somewhere between red and magenta.
How does that work with the resistance?

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

'Hello.'
Richard.

Quote:

The color is somewhere between red and magenta

.
Sorry, I meant the colors of the wires on the plug.
If the mass airflow sensor (MAF) from a 1.9 TDI engine fits mechanically with the connector and housing, I estimate the chances of permanently simulating a high air mass using a resistor are rather low.

Quote:

the control unit recognized it as incorrect

How was it expressed?

Have you personally driven a Passat V6 TDI from which this mass airflow sensor came?

Best regards, Rainer.

Yes, that one also worked perfectly fine.
The colors are: white and blue / white and red / yellow and brown / white and red / white and brown.
What resistance value should be connected to what is likely pin 5?

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

'Hello.'

Richard.

Hello Richard,

Please read the following post:
/viewtopic.php?t=954&highlight=resistance+MAF

You should be able to find information about the pin configuration of the mass airflow sensor (MAF) by using the search function.
Unfortunately, I don't have a wiring diagram for your specific device, but the output signal should be relatively easy to determine using a multimeter.
It is measured against a reference and ranges between 0 and 5V. When the accelerator pedal is pressed, the voltage increases.

Best regards, Rainer.

Hello,

I tried something with the diode, and the car seems to respond better to the accelerator now.
I only noticed an improvement when driving on the highway.
My further observations:
Does it make the same noise whether the MAF sensor is plugged in or disconnected?
The VTG (Variable Turbine Geometry) is not adjusted to its maximum setting during engine start-up and idle, but remains slightly below that point, approximately half a centimeter.

How can I check if the crankshaft ventilation system is working properly?

greetings

Richard.

Hello Richard,

Did you happen to read the values for the mass airflow sensor (MAF) when you plugged in the "replacement" part?
I suspect that the mass airflow sensor (MAF) is not the only problem with your engine.
Because if your car drives poorly whether or not the mass airflow sensor (MAF) is connected, then something else must be wrong.
This effect surprises me a bit, because your mass airflow sensor (MAF) readings in the lower RPM range seemed plausible; what MAF reading are you seeing in the engine control unit (ECU) when the MAF sensor connector is disconnected?

Quote:

How can I check if the crankshaft ventilation system is working properly?

Simply disconnect the hose from the intake manifold and seal the hole in the intake manifold. There shouldn't be a strong draft coming out of the crankcase ventilation system; it's difficult to describe what is normal versus abnormal.
Please take the vehicle for a test drive with the disconnected hose.

Quote:

The VTG adjustment is not set to its maximum value during engine start-up and idle, but remains about half a centimeter below the maximum.

Are the vacuum hoses and pressure sensor okay? Is everything clear and not blocked? Is the solenoid valve for turbocharger boost control working correctly?

Best regards, Rainer.

Hello Rainer,

When I connected the diode, the ASR indicator came on.
and the air mass reading at VagComm is fixed at 1000 mg for both 'setpoint' and 'actual' values.

The perception of how well the car runs is subjective; yesterday, my wife drove the car and said it felt very powerful.
I've had a faulty mass airflow sensor (MAF) before, and the car felt much slower as a result.
It's full and hasn't even reached its enspeed yet, but this time it will.
Today I installed and measured the mass airflow sensor (MAF) in my Passat 1.9 TDI.
The air mass was at 850mg .

All hoses and the magnetic valve for turbocharger pressure regulation are okay.
Perhaps the VTG rod is too long. The solenoid valve is operating between 30% and 60%. What do you think?

Best regards.

Richard.

Hmm, I don't understand anymore, so was it driven differently with or without the attached LIM (likely meaning "Load Management Module" or similar)?

Quote:

Vacuum hoses and pressure sensor okay? Nothing is stuck? Magnetic valve for turbocharger pressure regulation okay?

Have you already ruled out this possibility?
Can the VTG adjustment be influenced to draw more towards maximum boost pressure using a vacuum pump or large syringe, compared to what happens at idle?

Best regards, Rainer.

Hi,

It runs the same with or without the attached mass airflow sensor, but you can't say it's sluggish; the air mass is between 500 and 600.
But if I connect the diode, it seems to stick better to the gas.
There are days when I drive my car and feel like it's finally running correctly, but then I turn on my laptop and the air mass reading is between 500 and 600.


I can pull the VTG adjustment lever upwards with the mouthpiece facing up.