New Holland ENG 3065 – Engine Control Unit (ECU): Cylinder 5 - Injector Cable Short circuit (Low Side to Battery)

The engine control module has detected that the low-side control circuit for the fuel injector on Cylinder 5 is shorted directly to battery voltage. This prevents the module from properly grounding the injector to fire it, resulting in a misfire, rough running, and a derated engine condition.

• T5 Series
• T6 Series
• T7 Series
• T8 Series
• T9 Series
• T6000 Series
• T7000 Series
• TS6 Series
• 3000 Series
• CR9090
• CX8080
• CX8090

1. 1

   Visually inspect the main engine wiring harness and the specific injector harness for Cylinder 5 for chafing, melted insulation, or areas where the harness may be rubbing against the engine block or valve cover.

2. 2

   Perform a harness isolation test: Disconnect the injector harness from the ECU and from the Cylinder 5 injector. Use a multimeter to check for continuity between the low-side pin of the Cylinder 5 injector connector and the positive battery terminal. If continuity exists, the harness is shorted.

3. 3

   Ohm test the Cylinder 5 fuel injector itself to ensure the solenoid hasn't failed internally and shorted out.

4. 4

   Inspect the ECU pins and the harness connectors for water ingress, corrosion, or bent pins, which can bridge circuits and cause a false short-to-battery reading.

1. 1

   Disconnect Power

   Always disconnect the negative battery cable before working on the high-voltage common rail injection electrical system.

2. 2

   Access the Harness

   Depending on the specific FPT engine model, the injector harness may pass through the rocker/valve cover. Remove any necessary engine cowling, intake piping, and the rocker cover to access the injector connections.

3. 3

   Remove the Old Harness

   Unplug the harness connectors from all fuel injectors and disconnect the main pass-through connector from the engine harness.

4. 4

   Clean the Area

   Ensure the mating surfaces for the rocker cover and the electrical connections are completely free of oil, dirt, and debris. Contamination can ruin sensitive injection components.

5. 5

   Install the New Harness

   Route the new injector wiring harness exactly as the old one was routed. Plug in each injector securely, ensuring the weather-sealed connections click into place.

6. 6

   Reassembly

   If the rocker cover was removed, reinstall it using a new rocker cover gasket. Torque all bolts to OEM specifications.

7. 7

   Finalize

   Reconnect the battery, turn the key to the ON position to allow the ECU to initialize, and use a diagnostic scan tool to clear the ENG 3065 fault code. Start the engine and verify smooth operation.