Massey Ferguson 4364.02 – Engine Control Unit (ECU): AdBlue™ or DEF system - Malfunction, irregularity in NOx emissions

The Selective Catalytic Reduction (SCR) system is experiencing very low NOx conversion efficiency. The system has detected that the amount of Nitrogen Oxides (NOx) leaving the tailpipe is higher than the permitted emissions threshold, meaning the DEF/AdBlue fluid is either not being injected properly, the fluid is degraded, the SCR catalyst is failing, or the NOx sensors are reading incorrectly.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 5708
• 5709
• 5710
• 5711
• 5712
• 5713
• 6615
• 6711
• 6712
• 6713
• 6714
• 6715
• 6716
• 6718
• 7714
• 7715
• 7716
• 7718
• 7719
• 7720
• 7722
• 7724
• 7726
• 8727
• 8730
• 8732
• 8735
• 8737
• 8740
• 7340
• 7344
• 7345
• 7347
• 7360
• 7370

1. 1

   Check for accompanying codes: Troubleshoot any other active fault codes first, specifically looking for DEF pump speed faults, DEF relay open circuits, or NOx sensor missing/timeout codes.

2. 2

   Inspect DEF/AdBlue fluid: Verify the DEF tank is full of fresh, uncontaminated fluid. Degraded or watered-down DEF will cause low conversion efficiency.

3. 3

   Check the DEF dosing injector: Remove the DEF injector from the exhaust pipe and inspect it for severe crystallization or blockage.

4. 4

   Inspect the NOx sensors: Check the upstream and downstream NOx sensors for heavy soot buildup, physical damage, or melted wiring harnesses.

1. 1

   Disconnect Power

   Disconnect the tractor's battery to prevent voltage spikes during the sensor replacement.

2. 2

   Locate the Sensor

   Locate the downstream NOx sensor on the exhaust system (after the SCR catalyst).

3. 3

   Remove the Sensor

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

4. 4

   Install the New Sensor

   Thread the new OEM NOx sensor into the exhaust bung. Tighten to the manufacturer's specified torque.

5. 5

   Reconnect

   Plug the sensor connector back into the factory harness and reconnect the battery.

6. 6

   Clear and Test

   Use a diagnostic tool to clear the 004364.02 fault code. Run the tractor through a forced regeneration or an SCR efficiency test to allow the ECU to stabilize the new sensor readings and verify the repair.