Case IH F-655-05 - ECU – Engine Control Unit (ECU): Open load error of injector in cylinder 5

The Engine Control Unit has detected that the electrical current to the cylinder 5 fuel injector is lower than expected. This condition typically points to an open circuit, which can be caused by a broken wire, a disconnected harness, or an internal failure of the injector solenoid itself.

• MAGNUM AFS Connect
• Magnum 235
• Magnum 255
• Magnum 285
• Magnum 340
• Steiger series
• Axial-Flow 7230
• Axial-Flow 8230
• Axial-Flow 9230
• Austoft 9900

1. 1

   Verify that the tractor's battery has not been improperly connected to an external power supply, which can cause erratic ECU behavior.

2. 2

   Check the cables and harness between the ECU and the cylinder 5 injector for chafing, breaks, or loose connector pins (an open circuit in the wiring is a primary cause).

3. 3

   Swap the cylinder 5 injector with the injector from another cylinder, clear the codes, and run the engine. If the fault moves, the injector is internally faulty. If it remains, the issue is in the wiring harness or ECU.

4. 4

   Use a diagnostic tool to perform a cylinder acceleration test to verify the mechanical contribution of cylinder 5.

1. 1

   Disassembly

   Remove the valve cover, rocker arms, fuel inlet tube, and the injector electrical harness. Remove the faulty cylinder 5 injector.

2. 2

   Preparation

   Ensure the copper sealing washer and rubber O-ring are properly installed on the new injector. Lubricate the O-ring with Vaseline or a similar assembly grease.

3. 3

   Installation

   Slide the new injector into the cylinder head. Ensure the fuel inlet tube hole in the injector perfectly aligns with the fuel inlet tube bore in the head. Push down until you hear an audible snap, confirming it is seated.

4. 4

   Fuel Inlet Tube

   Lubricate the O-ring on the fuel inlet tube. Slide it into the bore—the alignment dimples will snap into place when properly oriented.

5. 5

   Initial Torque

   Torque the new injector hold-down bolts to 9 Nm.

6. 6

   Tube Torque

   Torque the fuel inlet tube nut to 50 Nm.

7. 7

   Final Injector Torque

   Apply the final torque to the injector bolts by turning them an additional 75 degrees.

8. 8

   Electrical & Reassembly

   Reconnect the injector harness and torque the nuts to 1.5 Nm. Reinstall the rocker arms and valve cover.

9. 9

   Programming

   Connect your diagnostic tool and perform IMA (Injector Component) programming/coding to input the new injector's trim codes into the ECU.