ECU 004364.17 – Catalytic Converter Efficiency of SCR System Slightly Low. John Deere System Advisory.

ECU 004364.17 (ECU 4364.17)

Code: 004364.17

Shortcode: 4364.17


This diagnostic trouble code is set when the NOx value at the outlet of the SCR system is detected to be too high to start regeneration, indicating slightly low efficiency of the catalytic converter. This condition can affect the overall performance of the SCR system and its ability to reduce NOx emissions effectively.


The ECU may limit engine performance or adjust the operation of the SCR system to manage the high NOx levels, potentially impacting vehicle performance and emissions compliance.


  • Inspect DEF Quality: Ensure that the DEF used meets the required quality standards. Replace low-quality DEF with high-quality DEF.
  • Check SCR System Components: Inspect the SCR catalyst and other components for damage, blockages, or malfunctions. Clean or replace components as necessary.
  • Verify NOx Sensors: Use diagnostic tools to check the NOx sensors for proper operation and accuracy. Replace any faulty sensors.
  • Test DEF Injection System: Ensure that the DEF dosing unit and injection system are functioning correctly and delivering the proper amount of DEF.
  • Perform Manual Regeneration: Conduct a manual regeneration cycle to help clear any accumulated deposits in the SCR system.
  • Reset ECU and Monitor System: After addressing the issue, reset the ECU to clear the fault code and monitor the system to ensure the catalytic converter efficiency is restored.


Maintaining the efficiency of the SCR system is essential for reducing NOx emissions and ensuring compliance with environmental regulations. Regular inspections and maintenance can help prevent efficiency-related issues.

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