C205 AdBlue and NOx Issue

[dexxa05]

Also note that there are first and second generation NOx sensors that cannot be mixed.
So if you have a first/second generation NOx sensor, for example, you will also need to install the corresponding NOx 2 sensor.

I replaced the second NOx sensor with a new one from MB. If the first NOx sensor is the first generation, will it work?

 

[Mersovod]

The sensor variant (normal - slow) is coded in the engine control unit.

 

[Skelebob9]

I replaced the second NOx sensor with a new one from MB. If the first NOx sensor is the first generation, will it work?

No, both NOx sensors must be the same generation, although if you have XENTRY it will usually tell you that the NOx sensors are not compatible with each other.

If you have access to XENTRY Online, you can go to the Special Procedures tab in the engine control unit and run the procedure "Resetting of the AdBlue warning message". In most cases, this will run the SCN coding in the engine electronics (and sometimes in the SCR module) and then reset the light, even if you have a lot of faults like you have.

I did this once with TOPDON by manually coding the SCN code to the engine electronics and then running the SCR reset function.

 

[Handed3219]

To disable this fault code in the CRD3 ECU, you must first read (dump) the flash memory. This can be done using tools such as Magic Motorsport Flex, Autotuner or, as a more budget option, Scanmatik 2 PRO in combination with PCMflash (module 91 - CRD3).

Once you have the flash memory dump, you will need software like WinOLS to edit the file and disable the desired DTC. Had this problem a while ago when replacing the NOx sensor but the problem still persists.