Case IH 17874 (F-654-03) - ECU – Engine Control Unit (ECU): Short circuit error of injector in cylinder 4

The engine control system has detected a short circuit (either to ground or to a voltage source) in the electrical circuit responsible for firing the fuel injector on cylinder number 4.

• VESTRUM CVX
• 240 Series Axial-Flow Combines (7240, 8240, 9240)
• Austoft 9900 Sugarcane Harvesters
• Steiger series tractors
• Magnum series tractors

1. 1

   Check for Bank-Wide Faults: Determine if fault code 3218 (DTC 7216) - Injection bank 2 short circuit failure is also present, as a short in one injector can affect all injectors on the same electrical bank.

2. 2

   Inspect the engine wiring harness leading to the cylinder 4 injector for rubbed-through insulation, pinched wires, or melted connectors.

3. 3

   Use a multimeter to test the cylinder 4 injector circuit for continuity to ground or a short to power.

4. 4

   Test the internal resistance of the cylinder 4 injector itself to see if the short is internal to the injector solenoid.

1. 1

   Power Down

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

2. 2

   Access the Injector

   Remove the necessary engine covers or valve covers (depending on the specific FPT engine model) to access the fuel injectors and their wiring harness.

3. 3

   Harness Repair/Replacement

   If the diagnostic tests indicated a short circuit in the wiring, repair the damaged section of the wire harness or replace the harness entirely as required.

4. 4

   Injector Replacement

   If the wiring harness tests good but the injector solenoid is internally shorted, remove the high-pressure fuel line and retaining clamp for cylinder 4, extract the faulty injector, and install a new one.

5. 5

   Reassembly & Calibration

   Reinstall all removed components. Note that installing a new common-rail injector usually requires entering the new injector's calibration code (IQA code) into the Engine ECU using a diagnostic tool.

6. 6

   Clear Codes

   Reconnect the battery, clear the fault code memory, and run the engine to verify the repair.