Case IH F-653-03 - ECU – Engine ECU: Short circuit error of the injector in cylinder 3

The engine controller has detected an electrical short in the circuit operating the #3 cylinder fuel injector.

• MAGNUM AFS Connect
• 240 Series Axial-Flow (7240, 8240, 9240)
• Magnum 235–340 (Series 4)
• Steiger Series (350–600 HP)
• Puma Series (130-185)
• Maxxum Series
• Austoft 9900
• A8000
• A8800
• Patriot 3230
• Patriot 3320
• Patriot 3330

1. 1

   Check for multiple injector short circuit codes (e.g., Cylinder 1 or 2) to rule out a shared harness short or ECU bank driver failure

2. 2

   Visually inspect the wiring harness between the Engine ECU and the cylinder 3 injector for chafing, melted insulation, or pinched wires

3. 3

   Disconnect the injector harness and measure the resistance across the injector solenoid terminals to determine if the short is internal to the injector

4. 4

   Test the harness for continuity to ground (High side to ground short) and continuity to battery voltage (Low side to battery short)

1. 1

   Power Down

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

2. 2

   Isolate the Circuit

   Disconnect the wiring harness connector directly at the cylinder 3 fuel injector.

3. 3

   Test the Harness

   Using a multimeter, check the harness side for shorts to ground or shorts to power.

4. 4

   Repair Wiring

   If a short circuit is indicated in the wiring, repair the damaged section of the wire harness or replace the harness entirely.

5. 5

   Replace Injector

   If the wiring harness tests good, the short circuit is internal to the injector solenoid. Remove the high-pressure fuel lines, remove the injector hold-down clamp, and extract the cylinder 3 injector. Install a new injector with new seals/crush washers.

6. 6

   Reassemble and Calibrate

   Reconnect the harness and fuel lines. Note: Common rail injectors often require the new injector's calibration code (IQA code) to be programmed into the ECU using a diagnostic scan tool.

7. 7

   Clear Codes

   Reconnect the battery, turn the key on, and clear the fault code memory from the ECU.