Case IH F-1442-05 - ECU – Engine Control Unit (ECU) / EDC: Fuel metering unit has an open load error

The control module has detected an open circuit (current below normal or a broken connection) in the circuit that drives the fuel metering unit. An open load means the electrical path is physically broken, either due to a severed wire, an unplugged connector, or a burnt-out internal solenoid coil.

• MAGNUM AFS Connect
• 240 Series Axial-Flow Combines
• Magnum Series
• Puma Series
• Farmall Series

1. 1

   Check for accompanying active codes (such as DTC 1565 for fuel rail pressure exceeding limits) and diagnose those first

2. 2

   Verify that the tractor's battery power supply has not been connected to an external power supply. If connected, disconnect it and test for normal operation

3. 3

   Inspect the wiring and connectors at the fuel metering unit (MeUn) and the EDC harness for loose contacts, corrosion, or backed-out pins

4. 4

   Measure the resistance across the pins of the fuel metering unit using a multimeter (an infinite/OL reading confirms the internal solenoid coil has failed)

1. 1

   Disconnect Power

   Disconnect the machine's battery to prevent electrical shorts during repair.

2. 2

   Harness Repair

   If the diagnostic checks revealed a broken wire or damaged connector plug between the EDC and the fuel metering unit, splice/repair the wiring harness or replace the connector pigtail.

3. 3

   Replace the Fuel Metering Unit

   If the wiring is intact but the unit failed the resistance test, clean the area around the high-pressure fuel pump to prevent contamination. Remove the mounting fasteners for the fuel metering unit and extract it from the pump.

4. 4

   Installation

   Lubricate the O-rings on the new fuel metering unit with clean diesel fuel. Carefully insert it into the high-pressure pump and torque the fasteners to OEM specifications.

5. 5

   Reassembly and Clearing Codes

   Reconnect the electrical harness and the battery. Use the Case IH Electronic Service Tool (EST) to clear the inactive fault codes and reset any self-learning parameters in the EDC.

6. 6

   Validation

   Start the engine and verify that the fault code does not return and that the fuel rail pressure operates within the desired limits.