Case IH F-174-31 - ECU – Engine Control Unit (ECU) / Engine Control Module (ECM): Torque limitation due to excessive fuel temperature

This code is triggered when the system measures a fuel temperature that exceeds the maximum allowable limit. Because excessively hot fuel reduces fuel viscosity—which negatively impacts injection timing and overall combustion efficiency—the system actively limits engine torque to protect the fuel system and engine components from damage.

• MAGNUM AFS Connect
• Magnum 400
• 240 Series Axial-Flow Combines
• 7240
• 8240
• 9240

1. 1

   Verify if the high temperature reading is plausible (check for extreme operating conditions, engine misuse, or running with very low fuel levels which prevents adequate cooling).

2. 2

   Inspect the fuel temperature sensor wiring harness for broken or disconnected wires.

3. 3

   Check the wiring for a short circuit to ground or a short circuit to an external voltage source.

4. 4

   Test the physical signal plausibility of the fuel temperature sensor to see if it is reading accurately compared to actual temperatures.

5. 5

   Verify the ECM programming, as incorrect flashing or an internal ECM defect can falsely trigger this code.

1. 1

   Visually inspect the fuel temperature sensor and its electrical connector for corrosion, moisture, or physical damage.

   The sensor is often located on or near the fuel filter housing.

2. 2

   Repair the damaged section of the wire harness.

   Perform this if a wiring fault (open circuit or short circuit) is found during multimeter testing.

3. 3

   Replace the fuel temperature sensor.

   Perform this if the wiring is intact but the sensor fails accuracy testing or reads out of bounds.

4. 4

   Reprogram/flash the ECM.

   Perform this if the sensor and wiring are fully functional but the code persists.

5. 5

   Replace the ECM.

   Perform this if reprogramming does not resolve a false trigger, indicating the ECM has an internal defect.