Case IH 19415 – DCU: Empty UREA Tank / DEF Level Sensor Failure

The system has detected that the Diesel Exhaust Fluid (DEF / Urea) level in the tank has dropped below the critical reserve limit (Limit 2) or is completely empty. If the tank is physically full, this code indicates a failure of the DEF level sensor (sending unit) falsely reporting an empty tank to the system.

• Tier 4a
• Tier 4b
• Case IH Magnum Series
• Case IH STX Steiger Series
• Case IH Puma Series

1. 1

   Manual Level Verification: Physically check the DEF tank level. Compare the actual fluid level in the tank to what the sensor is reporting to the cab display/DCU.

2. 2

   Fluid Quality Check: Inspect the DEF fluid quality. Ensure it is ISO 22241 compliant (32.5% urea concentration). Contaminated, diluted, or degraded fluid can cause chemical reactions that mimic a sensor failure or damage the sending unit.

3. 3

   Visual Wiring & Hardware Inspection: Examine the sensor wiring harnesses and connectors at the DEF header. Look for signs of corrosion, pin damage, or moisture intrusion. Inspect the top of the DEF header unit for physical cracks or heavy urea crystallization.

1. 1

   Refill the Tank

   Fill the urea tank with fresh, high-quality DEF. Clear the fault codes using an electronic service tool and cycle the ignition. If the code clears and the gauge reads accurately, the tank was simply empty.

2. 2

   Access the DEF Header

   If the tank is full but the code persists, the DEF level sensor (which is integrated into the DEF header/sending unit) has failed. Depending on the tractor's architecture, you will need to either drop the DEF tank or access the top flange assembly directly.

3. 3

   Remove the Faulty Sensor

   Disconnect the battery. Disconnect the electrical harness and the DEF fluid lines from the top of the header unit. Unbolt the flange and carefully pull the DEF header/level sensor assembly out of the tank.

4. 4

   Clean and Prep

   Clean the mounting surface on the tank. Always discard the old gasket, as reusing it will cause leaks.

5. 5

   Install the New Sensor

   Insert the new DEF level sensor/header unit into the tank with a new OEM gasket. Torque the flange bolts to OEM spec.

6. 6

   Reassemble and Test

   Reconnect the fluid lines and electrical harness. Turn on the machine, clear the DCU codes, and verify that the DEF gauge now accurately reflects the fluid level in the tank.