Case IH 3596 – Engine Control Unit (ECU) / Electronic Diesel Control (EDC) or Dosing Control Unit (DCU): Minimum urea level 2

This code indicates that the Diesel Exhaust Fluid (DEF / AdBlue) level in the tank has dropped below the secondary warning threshold. If ignored, this condition will eventually trigger an engine derate or inducement mode, limiting the machine's power until the fluid is replenished.

• Steiger
• Magnum
• Puma
• Maxxum
• Farmall
• Axial-Flow 7120
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230

1. 1

   Physically verify the DEF level in the tank. If the tank is empty, fill it with fresh DEF.

2. 2

   If the tank is full but the gauge reads empty, verify the DEF level sensor for malfunction or sticking due to DEF crystallization.

3. 3

   Inspect the wiring harness and the electrical connector at the DEF header unit for corrosion, moisture, or physical damage.

4. 4

   Ensure the DEF is not contaminated or degraded, as poor-quality fluid can damage the sending unit.

1. 1

   Power Down

   Turn off the machine and disconnect the battery to prevent electrical shorts.

2. 2

   Access the DEF Tank

   Depending on the machine architecture, you may need to drop the DEF tank or simply access the top mounting flange to reach the DEF header unit.

3. 3

   Disconnect Lines

   Disconnect the electrical connector and the engine coolant lines attached to the DEF header unit (the coolant lines are used to heat the DEF to prevent freezing). Note: Be prepared to catch minor coolant spills.

4. 4

   Remove the Header Unit

   Unbolt the flange assembly and carefully pull the DEF header unit out of the tank.

5. 5

   Inspect/Clean

   Inspect the sensor float/mechanism for heavy DEF crystallization. While it can sometimes be cleaned with warm distilled water, a failed internal sensor requires replacing the entire header unit assembly.

6. 6

   Install New Part

   Insert the new DEF header unit into the tank using a new flange seal/gasket to prevent leaks.

7. 7

   Reconnect

   Reattach the coolant lines and plug in the electrical harness.

8. 8

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic tool (such as CNH EST) to clear the fault codes. Verify that the DEF gauge now reads the correct fluid level.