Massey Ferguson 4364.01 – Engine ECU (Engine Control Unit): NOx Are High In The Exhaust (ECU) / Catalytic Converter Efficiency of SCR System Extremely Low

The Engine Control Unit has detected that the Nitrogen Oxide (NOx) levels at the outlet of the Selective Catalytic Reduction (SCR) system are too high. This indicates that the SCR catalyst is not converting emissions efficiently. When this code is active, the tractor's engine will typically enter a derated (electronically limited power) state to prevent excessive emissions.

• 7616
• 5612
• 7622
• Interim Tier 4 (2012-2015)
• 7614
• 5611
• 7615
• 5610
• 5613
• 7620
• 5609
• 7618
• 5608
• 7619
• 7626
• 7624
• 4600 Series
• 4700 Series
• 4607M
• 4609M
• 4707
• 4708
• 4709
• 4710
• 5600 Series
• 5700 Series
• 5708 through 5713 (SL/S)
• 6600 Series
• 6700 Series
• 6614
• 6615
• 6712 through 6718S
• 7600 Series
• 7700 Series
• 7714 through 7726S
• 8600 Series
• 8700 Series

1. 1

   Test DEF/AdBlue Quality: Low-quality, degraded, or diluted Diesel Exhaust Fluid is the most common cause of this code. Use a DEF refractometer to verify the fluid is exactly 32.5% urea.

2. 2

   Inspect the DEF Tank and Cap: Check for dirt, diesel fuel, or water contamination in the tank. Ensure the breather is not clogged.

3. 3

   Check DEF Lines and O-Rings: Inspect the heated supply and return lines for kinks, rub points, or damaged O-rings that could cause air ingress or pressure drops.

4. 4

   Inspect the DEF Doser/Injector: Remove the DEF injector from the exhaust and check for severe urea crystallization/blockage.

5. 5

   Check NOx Sensors: Inspect the upstream and downstream NOx sensors for heavy soot buildup or damaged wiring.

1. 1

   Address Fluid Issues

   If the DEF is contaminated or not at 32.5% concentration, drain the DEF tank completely, flush it, and replace the DEF pump filter. Refill with fresh, high-quality DEF.

2. 2

   Clean/Replace Components

   Clean the DEF injector nozzle with warm water if crystallized. If a NOx sensor is reading out of range or has failed completely, replace it.

3. 3

   Perform SCR System Verification Check

   Once physical repairs are made, the code will not clear on its own. You must connect a compatible diagnostic tool (such as AGCO EDT or Jaltest AGV) and initiate an SCR System Verification Check.

4. 4

   Run the Cycle

   This check acts similarly to a forced regeneration. It runs the engine under controlled temperature conditions to verify the efficiency of the SCR catalytic converter.

5. 5

   Clear Codes

   If the verification check completes successfully, the ECU will recognize the restored efficiency, the 004364.01 code will become inactive, and engine power will be restored.