New Holland ENG 3319 – Engine Control Unit (ECU / EDC): DM1DCU SPN2 message - Error in DCU active / DTC control error detected: Urea level in the tank below 5%

This code indicates that the Engine Control Unit (ECU) has received a Diagnostic Message 1 (DM1) over the CAN bus from the Dosing Control Unit (DCU) reporting an active SPN fault. It is triggered when the Diesel Exhaust Fluid (DEF) level in the tank has dropped below a critical threshold (typically 5%), warning the engine ECU that it cannot properly dose the SCR system.

• T6
• T7
• T8
• T9
• T7.185
• T7.200
• T8.380
• T9.615
• CR
• CX
• CR9090
• CX8080
• CX8090
• W170C
• W190C
• W230C
• L230

1. 1

   Visually inspect the DEF/AdBlue tank to verify if the tank is actually empty or below the 5% mark.

2. 2

   If operating in freezing temperatures, check if the DEF fluid has frozen, as a failed heater can cause the sensor to read frozen fluid as an empty tank.

3. 3

   Inspect the wiring harness between the DCU and the DEF tank level/temperature sensor for chafed wires, corrosion at the connectors, or rodent damage.

4. 4

   Using a multimeter, check the resistance between the DCU connector pins and the DEF tank level sensor connector pins.

5. 5

   Ensure there are no other active CAN timeout codes (such as 3555) which would indicate a severed communication line rather than a fluid level issue.

1. 1

   Refill the DEF Tank

   Refill the DEF tank with fresh, uncontaminated Diesel Exhaust Fluid meeting ISO 22241 standards.

2. 2

   Cycle the Key and Clear Codes

   Turn the ignition key to the ON position without starting the engine. Allow the DCU to prime and the DEF gauge to register the new fluid level. Use the New Holland Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the 3319 fault code.

3. 3

   Test the Level Sensor

   If the tank is full but the code remains active (and the gauge reads empty), disconnect the DEF level sensor. Test the connector for the proper 5V reference voltage from the DCU.

4. 4

   Repair Wiring

   If voltage is missing, trace the harness back to the DCU and repair any broken or shorted wires.

5. 5

   Replace the DEF Sending Unit

   If the wiring is intact and voltage is present, but the sensor fails to read the fluid level, the DEF tank header/sending unit has failed internally and must be replaced.

6. 6

   Replace the DCU

   If the sensor and wiring test perfectly, but the DCU still reports an internal error or fails to process the level signal, the Dosing Control Unit itself may require replacement. Note: A new DCU requires software installation and password authorization via CNH EST.