Case IH F-4354-14 - ECU – ECU or BCU: DEF/AdBlue pressure line heater failure and DEF/AdBlue tank temperature is too low

The system has detected that the heater for the DEF pressure line is failing to operate correctly (often due to defective conductivity, an open circuit, or a short circuit) while the DEF tank temperature is simultaneously reading below acceptable operating limits.

• MAGNUM AFS Connect
• Austoft 9900
• Magnum
• Puma
• Maxxum
• Farmall
• Steiger
• Quadtrac
• Luxxum
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230

1. 1

   Check the vehicle's battery voltage and overall power supply to ensure it is within normal operating limits.

2. 2

   Inspect the wiring harness connecting the ECU to the DEF pressure line heater for any short circuits (to ground or battery) or open circuits.

3. 3

   Check the power stage of the ECU for the DEF heater actuator.

4. 4

   Test the DEF pressure line heater for defective conductivity (resistance too high or too low).

5. 5

   Verify the CAN configuration in the Denox (DEF) system and ensure the DCU15 controller is correctly connected to the network and receiving proper voltage.

1. 1

   Address battery or wiring issues

   Address any underlying battery or wiring harness issues found during the diagnostic checks.

2. 2

   Check and replace DEF pressure line heater

   If the wiring and voltage are correct but the fault persists, check and replace the DEF pressure line heater.

3. 3

   Check UREA backflow line

   If replacing the heater does not resolve the issue, check the UREA backflow line for blockages, freezing, or damage.

4. 4

   Replace UREA Backflow Line

   Replace the UREA Backflow Line if it is found to be defective or if the failure is still present after heater replacement.

5. 5

   Clear fault codes

   Clear the fault codes using an OBD scan tool and verify that the system's comprehensive components read as 'ready'.