John Deere 4364.01 – Engine Control Unit (ECU): Catalytic Converter Efficiency of SCR System Extremely Low

The Engine Control Unit (ECU) detects that the Nitrogen Oxide (NOx) value at the outlet of the Selective Catalytic Reduction (SCR) system is too high. This indicates that the exhaust aftertreatment system is not effectively converting and cleaning the exhaust gases, which typically results in an engine derate.

• 5085E
• 5090E
• 5090EL
• 5100E
• 5090M
• 5100M
• 5100MH
• 5100ML
• 5115M
• 6110M
• 6120M
• 6130M
• 6145M
• 6155M
• 6175M
• 6195M
• 6110R
• 6120R
• 6130R
• 6145R
• 6155R
• 6175R
• 6195R
• 6215R
• 6105M
• 7210R
• 8R 410
• 9470RT
• 9520RT
• 9570RT
• S680
• S780
• T550
• W235
• 8400
• 8600
• 9800
• R4038
• R4040I
• R4045
• 130G
• 160G LC
• 333G
• 750 Dozer

1. 1

   Test DEF fluid quality for contamination, improper storage, or incorrect concentration (causes over 60% of these faults)

2. 2

   Inspect for exhaust leaks upstream of the downstream NOx sensor, especially between the DOC/DPF/SCR and at sensor bungs

3. 3

   Remove and inspect the DEF injector (doser) for white crystallization buildup blocking the spray pattern

4. 4

   Check the ECU software version to see if a calibration update (e.g., SW62275H) is required to prevent false positives

5. 5

   Use a diagnostic tool to monitor the inlet and outlet NOx sensors for erratic readings or drifting

1. 1

   Address Fluid Issues

   If the DEF is contaminated or degraded, drain the DEF tank completely, flush it, and refill it with fresh, high-quality DEF.

2. 2

   Clean or Replace the DEF Injector

   If the DEF doser is clogged with crystallized urea, clean it thoroughly. If it is damaged or fails to actuate properly during a dosing test, replace the injector.

3. 3

   Replace Faulty Sensors

   If the DEF system is clean and functioning but the outlet NOx sensor is still reading out of range, replace the downstream NOx sensor.

4. 4

   Update Software

   Flash the Engine ECU with the latest software calibration to resolve any known short-regen intervals or false-positive 4364.01 triggers.

5. 5

   Perform SCR System Verification Check

   Once the physical repairs are made, use a diagnostic tool to initiate an 'SCR system verification check' (which functions similarly to a forced regeneration). This tests the SCR catalytic converter's effectiveness at controlled temperatures. If the check completes successfully, the error will become inactive, and full engine power will be restored.