Case IH 19162 – Engine Control Unit (ECU): Replace DEF/AdBlue Quality Sensor - Internal Open circuit of the temperature sensor located in the DEF/AdBlue Quality sensor

The Engine Control Unit has detected an open electrical circuit specifically within the temperature-sensing portion of the DEF (Diesel Exhaust Fluid) Quality Sensor. Because the temperature sensor is integrated internally into the DEF quality sensor assembly, the system cannot accurately read the temperature of the urea fluid, which is critical for dosing calculations and freeze-protection heater operation.

• Tier 4b
• Axial-Flow 5130
• Axial-Flow 6140
• Axial-Flow 7140
• Axial-Flow 7230
• Axial-Flow 240 Series
• Magnum 380 CVT
• T7 Series
• Farmall

1. 1

   Check for accompanying codes that might indicate a broader CAN bus or power issue, such as 19144 or 19142.

2. 2

   Disconnect the DEF Quality Sensor connector and inspect the pins for corrosion, pushed-back terminals, or water intrusion.

3. 3

   Verify the wiring harness between the ECU and the DEF Quality Sensor for any breaks or chafing that could simulate an open circuit.

4. 4

   Connect the Case IH EST to monitor the DEF temperature parameter. If the reading is completely missing or pegged at a default extreme value, and the wiring harness tests good, the internal sensor has failed.

1. 1

   Preparation

   Turn off the machine and ensure the key is removed. Clean the area around the top of the DEF tank to prevent dirt from falling into the tank.

2. 2

   Drain Fluid (If Necessary)

   Depending on the mounting location of the sensor on your specific model, you may need to drain the DEF tank so the fluid level is below the sensor flange.

3. 3

   Disconnect

   Unplug the electrical connector from the DEF Quality Sensor. Disconnect any DEF fluid lines attached to the header unit, capping them to prevent contamination.

4. 4

   Removal

   Unbolt or unthread the DEF Quality Sensor assembly from the DEF tank and carefully pull the unit out.

5. 5

   Installation

   Insert the new DEF Quality Sensor into the tank. Secure the flange/lock-ring to the specified torque.

6. 6

   Reassembly

   Reconnect the DEF fluid lines and the electrical connector. Refill the tank with clean, uncontaminated DEF.

7. 7

   System Reset

   Because this fault causes an emissions inducement (engine derate), you must use the Case IH Electronic Service Tool (EST) to clear the fault codes and perform an 'Inducement Unlock / Counter Reset' to restore the machine to full power.