Error message 30E9 is very specific, and it could be registered only in error message memory of MSD80 control unit for N43/N53 engines. Only these engines have NOx system with NOx catalytic converter included in it.


Why is the error message 30E9 registered?

MSD80 measures the content of NOx in the exhaust gases, using NOx sensor. MSD80 is able to determine the performance abilities of NOx converter, observing the amount of NOx, the growth rate of NOx amount after regeneration sessions of NOx catalytic converter. If the performing ability is lower than allowed for a long while, MSD80 will record the error message 30E9.


What are the consequences in case of error message 30E9?

The engine performs only in Homogeneous mixture mode (Homogeneous lean and Stratified charge are not allowed) – the fuel consumption increases. In a longer while the engine will start to perform unevenly, misfires appear, error messages regarding Lambda probe trim can be recorded, the engine is not able to maintain necessary fuel mixture. Read more here.


Can the error message 30E9 be deleted?

No, the error message 30E9 cannot be deleted, its status is always active. Even after deleting it, it will appear in the error message list again, immediately.


What to do, when the error message 30E9 has been recorded?

You have two options:

  1. installation of new NOx catalytic converter, or:
  2. replacement of OEM NOx sensor with NOXEM.


Note. The average lifetime of NOx catalytic converter is around 150.000km. Increased oil consumption (more than 300 .. 400g/1000km), problems with NOx sensor or other systems (relating to fuel mixture, engine temperature, etc) may damage NOx catalytic converter.


Related entries:

NOx catalytic converter regeneration and desulphation

30EA nitric oxide catalytic converter, sulphurized

N43/N53 operation modes. Stratified charge performance check

Encoding of new NOx sensor

Encoding of new NOx catalytic converter