Case IH 3445 (F-519869-31) - ECU – Engine Control Module (ECM / Engine ECU): Torque limitation due to excessive fuel temperature

The engine's fuel temperature sensor has detected that the diesel fuel temperature has exceeded the maximum safe operating threshold. Because hot diesel fuel loses its viscosity and lubricity, it can cause catastrophic damage to the high-pressure fuel pump and fuel injectors. To protect these components, the system automatically triggers a derate (torque limitation), reducing engine power until the temperature drops to a safe level.

• VESTRUM CVX
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Steiger
• Magnum
• Puma
• Maxxum
• Farmall

1. 1

   Check Fuel Level: Extremely low fuel levels in the tank can cause this code because the small volume of fuel absorbs heat rapidly and overheats.

2. 2

   Check for Related Sensor Codes: Look for companion codes such as 3015 or 3016, which indicate an electrical fault rather than an actual temperature issue.

3. 3

   Plausibility Check: Check the fuel temperature reading on your diagnostic tool when the engine is completely cold to see if the sensor or wiring is faulty.

4. 4

   Wiring & Harness Inspection: Inspect the wiring harness leading to the fuel temperature sensor (B-017 or B-36) for chafing, broken wires, or a short circuit to ground/external power.

5. 5

   Fuel Cooler Inspection: If equipped, ensure the fuel cooler fins are not packed with dirt, chaff, or debris.

1. 1

   Clean the Area

   Locate the fuel temperature sensor (typically mounted on the fuel filter housing, fuel rail, or high-pressure pump housing). Clean the surrounding area thoroughly to prevent dirt from entering the fuel system.

2. 2

   Disconnect the Battery

   Disconnect the negative battery terminal to prevent electrical spikes.

3. 3

   Remove the Sensor

   Unplug the electrical connector from the sensor. Using the appropriate wrench, carefully unscrew the fuel temperature sensor. Note: Have a rag ready, as a small amount of fuel may leak out.

4. 4

   Install the New Sensor

   Thread the new sensor into the housing by hand to prevent cross-threading, then tighten to the OEM torque specification.

5. 5

   Reconnect and Prime

   Reconnect the electrical harness. Reconnect the battery. Turn the key to the 'ON' position for a few cycles to allow the electric lift pump to prime the fuel system and purge any air.

6. 6

   Clear Codes and Test

   Use a diagnostic tool to clear the 3445 fault code. Start the engine, check for fuel leaks around the new sensor, and run the machine under load to ensure the torque limitation has been lifted and the code does not return.