New Holland DCU 19325 – DCU: UREA Temperature in Tank out of range

This code indicates that the temperature of the Diesel Exhaust Fluid (DEF/Urea) inside the storage tank has exceeded the permissible operating range, or the sensor itself is providing an implausible reading to the system.

• T6 series
• T7 series
• T8 series
• CR series (CR6.80, CR7.90, CR8.90, CR9.90)
• W190B
• Magnum
• Steiger
• 721F-921F Wheel Loaders

1. 1

   Check DEF fluid level — low fluid cannot dissipate heat from the dosing module return line, causing the tank temperature to spike (low fluid cause).

2. 2

   Inspect the Coolant Control Valve (CCV) — check if the coolant lines at the DEF tank are hot when the ambient temperature is warm, which indicates a stuck-open or leaking valve (overheating cause).

3. 3

   Test the CCV — blow through the inlet while holding the bottom port closed to ensure it is sealing correctly.

4. 4

   Inspect the DEF Head Unit — if the tank is full and the CCV is functioning normally, the temperature sensor integrated into the DEF sending unit has likely failed (sensor failure cause).

1. 1

   Top off the DEF Tank

   If the tank is low, fill it with fresh, certified DEF and run the machine to see if the temperature normalizes and the code clears.

2. 2

   Address the Coolant Control Valve (if faulty)

   Disengage all drives, shut off the engine, and allow the machine to cool. Locate the Coolant Control Valve on the coolant lines routing to the DEF tank. If the valve is stuck open or leaking, drain the localized coolant, remove the faulty valve, and install a replacement CCV. Erase the fault code and test the operation.

3. 3

   Replace the DEF Head Unit (if the sensor has failed)

   Disconnect the electrical harness and fluid lines from the top of the DEF tank. Unbolt and carefully remove the old DEF Head Unit from the tank. Install the new DEF Head Unit, ensuring the O-ring/gasket is properly seated to prevent contamination. Reconnect the fluid lines and electrical harness. Clear the DCU 19325 / P205B fault codes using an Electronic Service Tool (EST) and verify normal temperature readings.