Adblue failure, what next?

The SCR (Selective Catalytic Reduction) system with AdBlue is a technology for reducing nitrogen dioxide (NOx) emissions in trucks, buses and passenger cars .

The SCR system works in the following way: AdBlue, a urea solution, is added to the exhaust gases, which is a catalyst for a chemical reaction with NOx. As a result, NOx is reduced to nitrogen and hydrogen . AdBlue is added to the exhaust gases before the catalyst, and then injected into a special SCR catalyst, where a chemical reaction and NOx emission reduction take place.

The most common errors accompanying SCR Adblue system failures:

The most common diagnostic errors (DTC) for AdBlue (SCR, Selective Catalytic Reduction) systems are:

1. Errors related to NOx sensors:

P2200 - P2204 : NOx sensor circuit problems.

P229F : NOx sensor fault.

P2A00 : NOx sensor problem, signal out of range.

P204F : Incorrect NOx reduction system performance.

2. AdBlue dosing system errors:

P20E8 : Low pressure in the AdBlue system.

P20E9 : Pressure in AdBlue system too high.

P2047 - P2049 : AdBlue injector circuit problem.

P2033 : AdBlue injector overheating.

3. Errors related to the quality or presence of AdBlue:

P207F : AdBlue quality not in accordance with requirements.

P20EE : Incorrect SCR catalyst efficiency (often related to AdBlue quality).

P203F : Low AdBlue level in the tank.

4. Temperature and AdBlue level sensor errors:

P205B - ​​P205D : AdBlue level sensor problems.

P206A : Incorrect signal from AdBlue fluid quality sensor.

P20BD - P20BF : AdBlue fluid temperature sensor fault.

5. Errors related to the AdBlue pump:

P20E0 - P20E2 : Problem with AdBlue pump operation.

P20C0 : AdBlue pump mechanical jam.

6. System errors:

P16CF : AdBlue system communication problem.

P2BA9 : NOx emission limit exceeded - SCR system problem.

7. Other AdBlue related errors:

P2032 - P2034 : Exhaust gas temperature sensor before/after the SCR catalytic converter.

P2002 : Incorrect efficiency of the particulate filter (indirectly related to AdBlue).

P249C : Problems with the reagent injection system (e.g. AdBlue freezing).