Case IH 3565 – Engine Control Unit (ECU): Urea quality and urea warning level 1

The Selective Catalytic Reduction (SCR) system has detected an issue with the Diesel Exhaust Fluid (DEF / Urea). The system has triggered a Level 1 warning (inducement) because the DEF quality sensor has measured a urea concentration outside the required specification (typically 32.5%), or the Dosing Control Unit (DCU) has initiated a warning due to another active SCR-related fault code.

• Magnum series (235-340)
• Steiger series
• Puma
• Optum
• Maxxum
• Farmall
• Axial-Flow series (7230)

1. 1

   Check for Secondary Codes: Scan for other active codes first and diagnose those primary codes if present, as the ECU often activates code 3565 because the DCU initiated an inducement due to another fault code.

2. 2

   Test DEF Quality: Use a DEF refractometer to test the fluid in the tank. It must read exactly 32.5% urea.

3. 3

   Inspect for Contamination: Check the DEF tank for signs of contamination, such as dirt, water, or diesel fuel.

4. 4

   Inspect the DEF Header/Pump: Check the DEF tank header (which houses the quality/level sensors) and the DEF supply pump for severe crystallization or blockages.

1. 1

   Drain the DEF Tank

   If the DEF tests poorly on the refractometer or contamination is suspected, completely drain the DEF tank.

2. 2

   Flush the System

   If diesel fuel or severe contamination is found, flush the tank and the rubber lines leading to the exhaust system to prevent damage to the doser injector.

3. 3

   Replace the DEF Filter

   Remove and replace the main DEF filter cartridge (typically a small cartridge filter located near the supply pump).

4. 4

   Replace the DEF Header/Sensor

   If the fluid is perfectly clean and at the correct concentration but the code persists, the DEF quality sensor has likely failed. Replace the entire DEF header/sending unit.

5. 5

   Refill the Tank

   Fill the tank with fresh, unexpired, ISO 22241 certified Diesel Exhaust Fluid.

6. 6

   Clear Codes

   Connect the Case IH Electronic Service Tool (EST) to clear the fault codes and reset the SCR system.