Case IH F-1240-31 - ECU – Engine Control Unit (ECU): Fuel pump pressure has exceeded desired pressure limits.

The Fuel Metering Unit (FMU) controls the desired fuel flow to the high-pressure fuel rail and is adjusted by feedback from the engine control module. If the actual fuel pressure in the rail exceeds the requested/desired fuel pressure by a specific threshold (typically 100.0 bar or 1450.0 psi), the system assumes an over-pressurization condition or internal leak, and this fault is triggered.

• MAGNUM AFS Connect
• 240 Series (7240, 8240, 9240)
• CR10.90Z
• Steiger Quadtrac (420, 470, 500, 540, 580, 600, 620)
• Austoft 9900 Sugarcane Harvesters

1. 1

   Use the Electronic Service Tool (EST) to check for related active electrical faults (e.g., 3107/F-5447-03, 3912/F-5380-04, 3137/F-5380-05) and diagnose them first.

2. 2

   Inspect fuel injectors for internal leakage or physical obstruction.

3. 3

   Test the fuel rail pressure sensor and check its wiring harness for shorts or opens.

4. 4

   Test the Fuel Metering Unit (FMU) for internal failure or wiring issues.

5. 5

   Check the charge gear pump to verify it is not producing excessively high pressure.

6. 6

   Check the high-pressure pump for low feed efficiency.

1. 1

   Verify active faults

   Connect the Case IH Electronic Service Tool (EST) and verify all active fault codes. Address any FMU or pressure sensor electrical faults first.

2. 2

   Test manual fuel pressure

   Hook up manual fuel pressure test equipment to the fuel system.

3. 3

   Run EST fuel system tests

   Run through the EST fuel system tests. Specifically, check if the pressure relief valve is 'popping' (opening) at the correct specification.

4. 4

   Replace high-pressure fuel pump

   If the fuel pressure is confirmed to be out of spec, the relief valve is not popping correctly, and the high-pressure pump is failing to regulate, remove and replace the high-pressure fuel injection pump.

5. 5

   Clear codes and verify

   Clear the fault codes using the EST and run the engine to verify the fuel pressure remains within the desired limits.