Case IH F-655-03 - ECU – Engine Control Unit (ECU / ECM): Short circuit error of injector in cylinder 5

The Engine Control Module (ECM) has detected an abnormal operation, open circuit, or short circuit in the needle control valve circuit for the fuel injector on cylinder #5.

• MAGNUM AFS Connect
• 240 Series Axial-Flow (e.g., 7240, 8240)
• Austoft 9900 sugarcane harvesters
• Puma
• Magnum
• Optum
• Maxxum
• Farmall series
• Patriot series

1. 1

   Visually inspect the engine wiring harness and connectors leading to the cylinder 5 injector for signs of chafing, melting, damage, or corrosion.

2. 2

   Use a multimeter to check for continuity and resistance in the injector circuit to confirm if there is a hard short to ground, short to battery, or an open circuit.

3. 3

   Verify the voltage reference and ground circuits from the ECM to ensure proper power supply to the injector.

4. 4

   Use a diagnostic scan tool to perform a cylinder cut-out test to isolate the faulty injector.

5. 5

   Swap the cylinder 5 injector with an injector from another cylinder. If the fault code follows the injector, the injector has failed. If it remains on cylinder 5, the issue is in the wiring or ECM.

6. 6

   If available, use an oscilloscope to check the injector control signal coming directly from the ECM to ensure the driver circuit is functioning.

1. 1

   Disconnect power

   Turn off the machine and disconnect the battery to prevent electrical spikes during repair.

2. 2

   Repair wiring harness

   If multimeter tests indicate a short or open circuit in the harness, repair the damaged wire or replace the affected section of the injector wiring harness. Clean or replace any corroded connector pins.

3. 3

   Remove faulty injector

   If the diagnostic swap test or cut-out test proves the injector's internal needle control valve has failed, remove the valve cover (if required by engine model), disconnect the fuel lines and electrical connector, and extract the faulty injector from cylinder 5.

4. 4

   Install new injector

   Install the replacement injector using new O-rings and seals. Torque the hold-down bolt and fuel lines to OEM specifications.

5. 5

   Reassemble and prime fuel system

   Reconnect the wiring harness, reinstall the valve cover, and prime the fuel system to remove air.

6. 6

   Clear codes and verify

   Reconnect the battery, connect a diagnostic tool, clear the F-655-03 fault code from the ECM memory, and run the engine to verify the repair.