Case IH 19110 – DCU (Dosing Control Unit): UREA Temperature sensor in Tank (electrical) | signal low | P205C Reagent -tank temperature sensor (temperature of the Reagent -solution in the tank) - short circuit low

The control module is receiving a voltage signal from the Diesel Exhaust Fluid (DEF / Urea) tank temperature sensor that is below the acceptable threshold. This is typically caused by a short circuit to ground, low voltage in the sensor circuit, or an internal failure of the sensor itself.

• Tier 4a
• Case IH Magnum Tractors: 235, 260, 290, 315, 340 (Series 4)
• Case IH Steiger Tractors: 350, 400, 450, 500, 550, 600 (NA and QT models)
• Case IH Combines: 7230, 8230, 9230, 7120, 8120, 9240
• Case IH Farmall Tractors: 90C, 110U

1. 1

   Inspect the wiring harness between the DEF tank sensor and the DCU for chafed wires, rodent damage, or a short to ground

2. 2

   Inspect the electrical connector at the DEF head unit for moisture, corrosion, or bent pins that could cause a voltage drop or short

3. 3

   Check for contaminated or degraded DEF fluid, which can cause chemical reactions that damage the sending unit sensor

4. 4

   Verify if extreme environmental temperatures or heavy vibrations have physically damaged the sensor assembly

1. 1

   Preparation

   Turn off the machine and disconnect the battery to prevent electrical spikes.

2. 2

   Access the DEF Tank

   Locate the DEF tank and clean the area around the top of the tank to prevent dirt from falling into the fluid.

3. 3

   Drain Fluid (If necessary)

   Depending on the tank design and fluid level, you may need to drain the DEF tank.

4. 4

   Disconnect the Sensor

   Unplug the main electrical harness connector from the DEF Head Unit.

5. 5

   Remove the DEF Head Unit

   Unbolt or unscrew the DEF Head Unit assembly from the top of the DEF tank. Carefully pull the unit (which includes the suction tubes and sensor probes) out of the tank.

6. 6

   Install the New Unit

   Insert the replacement DEF Head Unit into the tank, ensuring the gasket/seal is properly seated to prevent leaks. Secure the mounting hardware.

7. 7

   Reconnect and Refill

   Reconnect the electrical harness. Refill the tank with fresh, uncontaminated DEF.

8. 8

   Clear Codes

   Reconnect the battery. Use the Electronic Service Tool (EST) or a compatible diagnostic scanner to clear the 19110 / P205C fault codes from the DCU.