Case IH 19514 – DCU (Dosing Control Unit) or Engine ECU: Urea tank temperature sensor plausibility error (dynamic / static) - Reagent tank temperature sensor out of range

The control module has detected that the temperature reading from the Diesel Exhaust Fluid (DEF) / Urea tank temperature sensor is implausible. This means the sensor's reported temperature is either drifting, stuck, or reading outside the normal operating range compared to ambient conditions or other system temperature sensors.

• Tier 4a
• Steiger 350
• Steiger 400
• Steiger 450
• Steiger 500
• Steiger 550
• Steiger 600
• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 315
• Magnum 340
• Puma 125
• Puma 210
• Maxxum series

1. 1

   Inspect the wiring harness leading to the DEF tank header unit for loose contacts, chafing, or broken wires.

2. 2

   Disconnect the DEF tank sensor connector and inspect for debris, corrosion, or water intrusion (often caused by aggressive pressure washing).

3. 3

   Using the CNH Electronic Service Tool (EST), perform a temperature plausibility test on a cold machine to ensure DEF temperature closely matches ambient air and engine coolant/oil temperatures.

4. 4

   If operating in freezing conditions, verify the DEF tank heating system is functioning and thawing the system in the allotted time.

1. 1

   Preparation

   Stop the engine, turn off the battery disconnect switch, and allow the machine to cool down completely.

2. 2

   Access the DEF Tank

   Locate the DEF header assembly, which is mounted on the top of the DEF/Urea tank.

3. 3

   Disconnect Lines

   Carefully disconnect the electrical connector from the DEF header. Disconnect the DEF suction, return, and coolant heating lines (if equipped). Note: Cap the fluid lines immediately to prevent contamination.

4. 4

   Clean the Area

   Thoroughly clean the top of the DEF tank around the header to prevent dirt or debris from falling into the tank when the unit is removed.

5. 5

   Remove the Header

   Unscrew the mounting bolts or the retaining locking ring securing the DEF header to the tank. Carefully pull the header assembly straight up and out of the tank.

6. 6

   Install the New Header

   Insert the new DEF header assembly into the tank, ensuring the new rubber gasket/seal is properly seated. Tighten the retaining ring or bolts to OEM torque specifications.

7. 7

   Reconnect

   Reconnect the DEF fluid lines, coolant lines, and the electrical connector.

8. 8

   Clear Codes

   Turn the battery disconnect switch back on. Connect the CNH Electronic Service Tool (EST), clear the 19514 / P205B fault codes, and verify that the DEF temperature reading is now accurate.