ECU 005298.01 – DOC Efficiency Extremely Low. John Deere System Advisory.

ECU 005298.01 (ECU 5298.01)

Code: 005298.01

Shortcode: 5298.01


This diagnostic trouble code indicates that the Diesel Oxidation Catalyst (DOC) efficiency is extremely low. This can affect the overall performance of the emissions control system, leading to higher emissions and potential damage to downstream components.


The ECU may limit engine performance to manage the low DOC efficiency and ensure emissions compliance. This could result in reduced engine power and performance.


  • Inspect DOC: Check the DOC for signs of damage, blockage, or excessive soot buildup. Clean or replace the DOC if necessary.
  • Check Fuel System: Ensure that the fuel system is operating correctly, and there are no issues causing improper combustion, such as injector malfunctions.
  • Verify Exhaust System: Inspect the exhaust system for leaks or other issues that could affect DOC efficiency.
  • Monitor Operating Conditions: Review operating conditions that might contribute to low DOC efficiency, such as excessive idling or poor fuel quality.
  • Perform Maintenance: Conduct regular maintenance to ensure the DOC and associated components are in good working condition.
  • Reset ECU and Monitor System: After addressing the issue, reset the ECU to clear the fault code and monitor the system to ensure DOC efficiency returns to normal.


Maintaining the efficiency of the DOC is crucial for optimal emissions control and engine performance. Regular inspections and timely maintenance can help prevent efficiency-related issues.

Control Units: John Deere

John Deere Parts
John Deere Logo