Case IH 19097 – Engine Control Unit (ECU) or Dosing Control Unit (DCU): DEF/AdBlue supply module temperature outside valid range

The temperature sensor located inside the Diesel Exhaust Fluid (DEF) supply module is reporting a temperature value that is implausible or outside the programmed operating parameters. This typically points to a failed internal temperature sensor, a wiring/communication issue, or extreme environmental conditions affecting the module.

• Tier 4b
• Magnum series (180 to 370)
• Steiger/Quadtrac series (350 to 600)
• Puma series (130 to 240)
• Maxxum series (110 to 150)
• Farmall series (95A, 100C, 110C, 115U)
• Patriot (4430)
• Titan series
• Austoft 9900
• Combines (5130 to 9230)
• Farmlift series
• 1150M crawler dozers

1. 1

   Connect a diagnostic scan tool and observe the live data for the DEF supply module temperature. Compare it to the ambient temperature to verify if the sensor reading is completely implausible (e.g., reading extreme hot or cold when the machine is off).

2. 2

   Check for accompanying codes that might indicate a broader electrical or heater issue, such as 19096 or 19098.

3. 3

   Inspect the control circuit and wiring harness connecting the ECU to the DEF supply module. Look for chafed wires, corrosion, or loose pins in the connector that could distort the temperature signal.

4. 4

   Turn off the ignition switch until communication with the diagnostic scan tool is discontinued, then turn it back on without starting the engine to see if the code resets or clears.

1. 1

   Depressurize and Power Down

   Turn off the ignition switch and wait for the DEF system to complete its purge cycle (returning fluid to the tank) and for the ECU to power down completely.

2. 2

   Clean the Area

   Thoroughly clean the area around the DEF supply module to prevent dirt or crystallized white urea crust from entering the open fluid lines.

3. 3

   Disconnect Electrical and Fluid Lines

   Disconnect the main electrical wiring harness from the DEF supply module. Carefully disconnect the DEF suction, pressure, and backflow lines.

4. 4

   Remove the Module

   Remove the mounting bolts securing the DEF supply module to its mounting bracket and remove the faulty unit.

5. 5

   Install the New Module

   Mount the replacement DEF supply module and secure the bolts.

6. 6

   Reconnect

   Reconnect the DEF fluid lines (ensuring they click securely into place) and plug in the electrical connector.

7. 7

   Clear Codes and Test

   Turn the ignition on, connect the diagnostic scan tool, and clear the 19097 fault code. Run the engine and perform a DEF dosing test via the scan tool to prime the system, verify the temperature reading is now valid, and check for leaks.