Case IH 17863 (F-653-04) - ECU – Engine Control Unit (ECU): Short circuit of low side of injector in cylinder 3

The engine's control system has detected that the low side (the ground/return circuit) of the electronic fuel injector for cylinder 3 is shorted to ground or another voltage source. This prevents the control module from properly regulating the fuel injection event for that specific cylinder, typically resulting in a misfire, rough running, and a derated engine state.

• VESTRUM CVX
• Austoft 9000
• Austoft 9900
• CR8090
• CR8.90
• Steiger
• Puma

1. 1

   Visual Inspection: Inspect the engine wiring harness routing from the Engine ECU to the cylinder 3 injector. Look for chafed insulation, pinched wires, or areas where the harness rubs against the engine block or valve cover.

2. 2

   Connector Check: Disconnect the cylinder 3 injector connector and the ECU connector. Check for oil intrusion, bent pins, corrosion, or moisture. (Note: On Cursor 11 engines, the Injector 3 'low' side is typically routed to ECU pin 2/75).

3. 3

   Wiring Short Test: Using a digital multimeter, measure the resistance between the cylinder 3 injector low-side wire and a known good chassis ground. Continuity to ground while unplugged indicates a short in the wiring harness.

4. 4

   Injector Coil Test: Measure the resistance across the injector pins to check for an internal short circuit within the injector solenoid coil itself. Test for continuity between the injector pins and the metal injector body (which should read as open/infinite resistance).

1. 1

   Turn off the machine, remove the key, and disconnect the battery's negative terminal.

2. 2

   Remove the engine valve cover (if necessary on your specific engine configuration) to access the internal injector wiring harness.

3. 3

   Disconnect the wiring harness from the cylinder 3 fuel injector.

4. 4

   If the short is in the wiring: Repair the damaged section of the wire or replace the engine injector wiring harness entirely.

5. 5

   If the short is internal to the injector: Remove the hold-down clamp and extract the faulty cylinder 3 injector.

6. 6

   Clean the injector bore thoroughly. Install the new injector with new O-rings and copper sealing washers. Torque the hold-down clamp to exact OEM specifications.

7. 7

   Reconnect the injector wiring harness and the ECU connectors.

8. 8

   Reinstall the valve cover with a new gasket.

9. 9

   Reconnect the battery, turn the key on, and use a diagnostic scan tool (such as the Case IH EST) to clear the 17863 (F-653-04) fault code.

10. 10

    Start the engine, check for fuel leaks, and verify that the engine runs smoothly without the code returning.