Ambient Pressure Sensor for VW G3 AFN ECU

Translated on 23-10-2026, 5:29.

Hello everyone,

Okay, it's happened to me too. I'm getting a non-erasable error code that says "control unit defective" intermittently. It seems to be the ambient pressure sensor. Has anyone found a source for this sensor where you can order it individually? Or perhaps someone has one lying around that they no longer need?

Greetings.
Reuselkopp.

Translated on 23-10-2026, 5:30.

hello,

The ambient pressure sensor is integrated into the mass airflow sensor (MAF), and it can be accessed/found [depending on the intended meaning].
Part number 074 906 461 can be purchased for approximately €120.00 at

.

Sincerely,
KeeSoft

Translated on 23-10-2026, 5:31.

by KeeSoft wrote:

The ambient pressure sensor is integrated into the mass airflow sensor (MAF), which can be accessed by...
Part number 074 906 461 can be purchased for approximately €120.00 at

.

No, it's not in the LMM (likely referring to a mass airflow sensor), and it never has been. The sensor is located in the engine control unit (ECU).

Translated on 23-10-2026, 5:32.

by KeeSoft wrote:

hello,

The ambient pressure sensor is integrated into the mass airflow sensor (MAF), and it can be accessed/found [here/there/etc.].
Part number 074 906 461 can be purchased for approximately €120.00 at

.

manufactured by KeeSoft

"Not applicable to the vehicle/control unit mentioned (for the initial G3 1Z models)."
(Possibly also Audi 80/A4 models with MSA12 without WFS, as there was something like that before).
@reusel:
I still have a dead MSA15 lying around. The sensor might still be working.

Best regards,
Micha

Translated on 23-10-2026, 5:33.

Hello everyone,

I'm bringing this thread back to the top.
Does anyone have a working ambient pressure sensor from an MSA15 that they're not using, or does anyone know a source where I can buy one? Currently, the ambient pressure sensor is only showing 690 mbar.

Greetings.
Reuselkopp.

Translated on 23-10-2026, 5:34.

If it doesn't work, just install a fixed resistor. If you don't have any tuning, it shouldn't matter, and you can extend the VGZ (which is also dependent on the ATM pressure) using VCDS.

Simply measure the voltage at the STG (under voltage, open), the middle pin is usually the signal output. You can optionally solder in a potentiometer and adjust the "desired" atmospheric pressure

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