AVF facing massive problems, no performance (Solution)

My Audi A4 B6 has been in the workshop for a week now, and no one can find a fault.

Here is the vehicle's log:

Furthermore, I'm seeing a blinking glow plug indicator on the display.
Block11:
Idle speed N75 always at 92-94% when stationary.
basically, it cannot be influenced even in the basic settings.

Block03: AGR (Average Grain Yield) should be 255 mg/H, but it is always around 440 mg/H.
Not affected by default settings.
AGR always at 4.8% at idle, N18.

Furthermore, the brake lights remain on continuously when the ignition is on.
We have already replaced the brake light switch, but there was no change.

Does anyone have any ideas?
The vehicle was in the workshop to have the drive shafts inspected, and after they were replaced, these errors appeared.

First, check the wiring harness for any damage, ensure proper grounding connections, and inspect the fuses.

Do these errors reappear after deleting the files, or do they persist?

If you provide us with precise data about the vehicle, it will be easier.

Harness fuses and ground connections all checked...
Everyone is okay.

What data is still needed?
Audi A4 B6 1.9 TDI AVF, but you can see all of that in the log. Year: 2001, Model: Avant.

Hello,

The errors are typical for mass-related problems of the actuators/sensors or their +12V power supply.
Therefore, further investigation is needed in this area.

Best regards, Rainer.

Thank you for the tip... I will continue searching.

Okay, so the Audi workshop said they didn't find any issues with the mass airflow sensor. The response from Meisters' workshop was, "It's possible that a control unit is defective."

ohhhh mannnn, it's always me who has to make such stupid mistakes that nobody can even find.

Kitwing wrote:

So... the Audi workshop stated that they did not find any mass problem. The response from Meisters' workshop was, "It's possible that a control unit is defective." ohhhh mannnn, it always has to be me making such stupid mistakes that nobody can even find.

Hello,

The error isn't "stupid," but fortunately, it's quite obvious and persistent. Take the multimeter and the circuit diagram and see where the problem lies.
It can't be that difficult to measure whether there is contact with +12V on one side of the actuators, or to determine the potential of the other side, and then trace the corresponding cable.

That the might replace the most expensive link in the chain instead of searching is economically understandable. Unfortunately, the control unit could very well be defective, but if you simply install a new one without fixing the underlying cause of the defect, what do you think will happen?

You have 2 options:

- Obtain and measure the circuit diagram.

or

- Going to a workshop is helpful if you have some idea of what you're actually doing.

Best regards, Rainer.

Okay, here's the solution.

I have checked all the mass storage locations, actuators, and sensors that produced the incorrect entries, as described by "dieselschrauber."
Everything is OK.

Okay, I've now removed the brake light switch that Audi already replaced and compared it to the old one... and sure enough, it has a different part number and fewer pins.

So, I went to Audi, and wouldn't you know it, it was the wrong one. They even had the correct part in stock, and after installation, all the errors were gone.

Thank you for your sympathy and support... now I just need to get rid of these lingering vibrations.

Thank you for the feedback .

Quote:

Furthermore, the brake lights illuminate continuously when the ignition is on. We have already replaced the brake light switch, but there was no change.

Strange - so I installed the wrong part twice - anyway.