New Holland 3593 – ECM: Low Quality of Reagent

The Selective Catalytic Reduction (SCR) system has detected that the Diesel Exhaust Fluid (DEF) has a urea concentration outside of the acceptable 32.5% range. This indicates the fluid is diluted, contaminated, or degraded. This fault can cause the engine to enter a derated or limp mode to ensure emissions compliance, reducing engine power and potentially halting field operations.

• T6
• T7
• T8
• T9
• Combines
• Grape Harvesters

1. 1

   Test DEF quality using a refractometer to ensure urea concentration is exactly 32.5%.

2. 2

   Visually inspect the DEF for signs of contamination, such as cloudiness or crystallization.

3. 3

   Inspect the DEF tank, lines, and connections for any signs of leaks.

4. 4

   Check the wiring harness and electrical connectors leading to the DEF quality sensor for damage, corrosion, or loose connections.

5. 5

   Check for any other active or inactive fault codes that could indicate related SCR system issues.

1. 1

   Drain DEF tank

   If the DEF is found to be of poor quality, completely drain the DEF tank.

2. 2

   Refill with quality DEF

   Refill the tank with fresh, high-quality DEF from a sealed container. Refill with the same amount of fluid that was drained to avoid confusing the system's sensors.

3. 3

   Clear fault codes

   Use a diagnostic tool to clear the active fault codes.

4. 4

   Perform system reset/relearn

   Start the engine and run at high idle (around 1000 RPM or higher) for a couple of minutes. Turn the engine and ignition off for at least one to two minutes. Restart the engine and monitor for the fault code. A short drive under load may be required to complete readiness monitors.

5. 5

   Replace DEF quality sensor

   If the fault code persists after confirming good DEF quality and performing a system reset, replace the DEF quality sensor. Clear codes and perform the relearn procedure again.