Case IH 19101 – DCU (Dosing Control Unit): UREA level sensor (electrical) signal high / P203D Reagent - tank level sensor - short circuit high

The signal voltage from the Diesel Exhaust Fluid (DEF) / Urea tank level sensor is too high. The system has detected a short circuit to a high voltage source in the sensor or its circuit.

• Tier 4a
• Case IH Steiger Series (350, 400, 450, 500, 550, and 600)
• Case IH Magnum Series 235 - 340 (Series 4)
• Case IH Puma Series

1. 1

   Visually check that the DEF/Urea level sensor is properly installed in the tank.

2. 2

   Inspect the wiring harness and electrical connectors running between the DEF level sensor and the DCU for chafed wires, melted insulation, or water intrusion.

3. 3

   Verify if the sensor signal is genuinely out of range (SRC high) due to a failed internal sensor component.

1. 1

   Repair Wiring

   If the diagnostic checks reveal damaged wiring or corroded connectors causing the short circuit, repair or replace the affected section of the harness.

2. 2

   Replace Sensor

   If the wiring harness is in good condition and the sensor is correctly installed but the code persists, the DEF level sensor itself has failed internally and must be replaced.

3. 3

   Clear Codes

   After the physical repair is complete, use an Electronic Service Tool (EST) to clear the DCU error codes. If you do not have the proper diagnostic tool, you may need to seek assistance from a certified Case IH mechanic.