Case IH F-656-03 - ECU – Engine Control Unit (ECU): Short circuit error of injector in cylinder 6

The system has detected that the electrical circuit for the cylinder 6 fuel injector has a short circuit on the low side or is shorted to a positive voltage source, preventing the injector from firing correctly.

• MAGNUM AFS Connect
• Axial-Flow 240 series
• Axial-Flow 6130
• Axial-Flow 7130
• Axial-Flow 7230
• Magnum 235
• Magnum 250
• Magnum 260
• Magnum 280
• Magnum 290
• Magnum 315
• Magnum 340
• Puma 130 through 230 series
• Maxxum
• Steiger
• Austoft 9900
• 621F
• 721F
• 821F
• 921F
• 1021F
• 1121F

1. 1

   Visually inspect the wiring harness and the connector at the cylinder 6 injector for corrosion, melting, or looseness caused by vibration and engine heat.

2. 2

   With the key OFF, disconnect the injector and the Engine ECU. Use a multimeter to check the cylinder 6 injector wiring for a short circuit to a positive voltage source (battery +) or a short to ground.

3. 3

   Measure the resistance across the pins of the cylinder 6 injector itself. If the resistance is zero or significantly out of specification compared to the other 5 injectors, the injector solenoid is internally shorted and must be replaced.

1. 1

   Safety First

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Injector

   Remove the engine valve cover or injector access panels depending on the specific FPT engine model.

3. 3

   Disconnect

   Unplug the electrical connector from the cylinder 6 injector. Remove the high-pressure fuel line connecting the common rail to the injector. Cap the rail fitting immediately to prevent contamination.

4. 4

   Remove the Injector

   Remove the injector hold-down clamp/bolt. Carefully extract the injector from the cylinder head.

5. 5

   Prep for Installation

   Clean the injector bore in the cylinder head. Ensure the old copper sealing washer is removed and not stuck at the bottom of the bore.

6. 6

   Install New Injector

   Install the new injector equipped with a new copper washer and O-rings. Torque the hold-down clamp to the OEM specification.

7. 7

   Reassemble

   Reinstall the high-pressure fuel line (it is highly recommended to use a new fuel line, as they are often single-use to prevent leaks) and torque to spec. Reconnect the electrical harness.

8. 8

   Programming

   Use the Case IH Electronic Service Tool (EST) to program the new injector's trim code (IQA code, found on the top of the new injector) into the Engine ECU.

9. 9

   Finalize

   Reconnect the battery, prime the fuel system, clear the F-656-03 fault code, and run the engine to check for leaks and misfires.