Polo 9N FSI engine control unit programming

Hello.

I have a Polo 9N FSI, manufactured in 2003, with engine code AXU.
"Because the vehicle is frequently driven short distances, I constantly receive the error code 17441 - NOx sensor (G295), P1033 - 35-00 - signal too low."
We have already replaced several NOx sensors in recent years.
I'm now having a problem where, when I install a new sensor (I still have 2 new ones), they simply don't respond at all. Read with VCDS.
All cables and connectors have been checked and tested.
A new flexible pipe has been installed in the exhaust system and checked for leaks.
NOx control unit replaced.
Since I still have another engine control unit (with the same OE number, AXU model, and software version), I wanted to test it to see if that might be the problem.
My question is how to do this using VCDS. Login codes for the speedometer and engine control unit are available.

Sure, here's the translation:

"LG" translates to "Best regards" or "Sincerely" in English.

Hello,

Unfortunately, at the moment, only older engine control units can be linked to the immobilizer using VCDS. This depends on the generation of the immobilizer.



I would suggest searching online for the VAG part number of your engine control unit to see if there is a newer software version available.
http://wiki.ross-tech.com/wiki/index.php/ImmobilizerSoftware version of the ECUhttps://wiki-ross--tech-com.translate.goog/wiki/index.php/Immobilizer?_x_tr_sch=http&_x_tr_sl=en&_x_tr_tl=de&_x_tr_hl=de&_x_tr_pto=wapp

Best regards, Rainer.

Hello.

Okay, hier ist die Übersetzung:

"This is about the immobilizer, Generation 3." Regarding the software version, there are no updates available beyond version 4884.


Best regards,
Jürgen

Fixed the second link above. Regarding the NOx error with a low signal: Is there a measured value within the engine control unit (ECU) where this can be checked?

This would greatly simplify the inspection of the wiring or the entire system.

Hello.

I checked the cables for continuity, but I'm not yet sure exactly which readings I should be looking for.

juergenp. wrote:

Hello. I have checked the cables for continuity.

However, I haven't yet figured out exactly which measurement values I should be paying attention to.
Whether the sensor is receiving its supply voltage, whether the output signal from the sensor is within the expected range, and whether it also arrives at the connector of the control unit in that manner.