Massey Ferguson E4364.02 – Engine Control Unit (ECU): NOx Are High In The Exhaust

Indicates a malfunction or irregularity in the AdBlue™/DEF (Diesel Exhaust Fluid) system's NOx emissions. The Selective Catalytic Reduction (SCR) system is experiencing very low NOx conversion efficiency, meaning the exhaust gases leaving the tailpipe contain higher levels of Nitrogen Oxides than permitted by emissions standards.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4707
• 4708
• 4709
• 4710
• 5708
• 5709
• 5710
• 5711
• 5712
• 5713
• 6615
• 6711
• 6712
• 6713
• 6714
• 6715
• 6716
• 6718
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7725
• 7726
• 8670
• 8680
• 8690
• 8727
• 8730
• 8732
• 8735
• 8737
• 8740
• Activa
• BETA
• PL-I Combines

1. 1

   Check for Accompanying Codes: Look for other active fault codes. If codes for the DEF pump (e.g., E4374), DEF relays (e.g., E4356), or NOx sensors (e.g., E521004 / E521005) are present, diagnose those first.

2. 2

   Verify DEF/AdBlue Quality: Test the DEF concentration using a refractometer (it should be 32.5%). Contaminated, diluted, or expired DEF fluid will fail to convert NOx properly.

3. 3

   Inspect the Exhaust System: Check for exhaust leaks between the engine turbocharger, the Diesel Oxidation Catalyst (DOC), and the SCR unit. Leaks can skew NOx sensor readings.

4. 4

   Test the DEF Dosing System: Verify that the DEF pump is building adequate pressure and that the DEF injector/doser is not clogged with crystallized urea.

5. 5

   Inspect NOx Sensors: Check the wiring harnesses for the upstream and downstream NOx sensors for chafing, melting, or poor connections.

1. 1

   Disconnect power

   Disconnect the tractor's battery or ignition source to prevent voltage spikes from damaging the ECU or the new sensor's integrated module during replacement.

2. 2

   Locate the sensor

   Identify the faulty NOx sensor (upstream before the DOC/SCR, or downstream at the exhaust outlet).

3. 3

   Remove the sensor

   Unplug the sensor's electrical connector from the vehicle harness. Use a specialized NOx sensor socket or a wrench to unthread the sensor probe from the welded bung in the exhaust pipe.

4. 4

   Install the new sensor

   Apply a small amount of anti-seize to the threads of the new sensor (if not pre-applied), being extremely careful not to get any on the sensor probe tip. Thread it into the exhaust bung and tighten to OEM torque specs.

5. 5

   Reconnect

   Plug the new sensor's module into the factory wiring harness. Reconnect the battery.

6. 6

   Clear codes and test

   Use a diagnostic scan tool to clear the E4364.02 fault code. Run the tractor through a forced regeneration or an SCR system test to allow the ECU to verify that NOx conversion efficiency has returned to normal parameters.