Case IH 19087 (DTC 8DAA) - ECU – EDC (Engine Data Controller) or VCM (Vehicle Control Module): DEF/AdBlue tank temperature is not within acceptable limits

This code indicates that the temperature reading from the Diesel Exhaust Fluid (DEF) tank is registering outside of the expected or plausible operating range. When the sensor reports an implausible temperature, the system will log this code and may eventually derate the engine to protect the Selective Catalytic Reduction (SCR) system.

• MAXXUM T4E
• 240 Series Combines (5130, 6130, 7130, 7230, 8230, 9230)
• Steiger
• Magnum
• Puma
• Maxxum
• Farmall
• Farmlift telehandlers
• 580SN backhoes

1. 1

   Perform a cold soak temperature comparison: let the machine sit overnight, then use a diagnostic scan tool to compare the DEF tank temperature reading to the ambient air temperature and engine coolant temperature. If the DEF temperature is drastically different, the sensor has failed.

2. 2

   Check for accompanying codes such as 19088 (Error supply module heater plausibility) or 19095 (DEF/AdBlue tank temperature sensor plausibility failure) to confirm the issue is localized to the header unit.

3. 3

   Inspect the wiring harness leading to the top of the DEF tank. Check the main electrical connector at the DEF header for corrosion, pushed-out pins, or wire chafing.

4. 4

   Check the DEF fluid quality to ensure it is not contaminated, as chemical reactions or crystallization can damage the sending unit.

1. 1

   Preparation

   Turn off the machine and disconnect the battery. Clean the area around the top of the DEF tank thoroughly to prevent dirt or debris from falling into the tank during removal.

2. 2

   Drain Fluid (Optional but Recommended)

   Depending on the tank's location and fluid level, you may want to drain some DEF to prevent spilling when the header is removed.

3. 3

   Disconnect Lines

   Carefully disconnect the DEF suction, return, and heater lines from the top of the header unit. Cap the lines immediately to prevent crystallization and contamination.

4. 4

   Disconnect Electrical

   Unplug the main electrical harness connector from the header.

5. 5

   Remove the Header

   Remove the mounting bolts or the locking ring securing the DEF header to the top of the tank. Carefully pull the header assembly straight up and out of the tank.

6. 6

   Install New Header

   Insert the new DEF header assembly into the tank, ensuring the new O-ring or gasket is properly seated to prevent leaks. Secure the mounting bolts/locking ring.

7. 7

   Reconnect

   Reconnect the DEF fluid lines and the electrical connector.

8. 8

   Clear Codes

   Reconnect the battery, turn the key on, and use a diagnostic scan tool to clear the 19087 (8DAA) fault code. Run the machine to verify the DEF temperature reading is now accurate and the system builds pressure without derating.