New Holland NH 3069 – Engine Control Unit (ECU): Injector solenoid valve Cylinder 3 - SOURCE HIGH

The engine control system has detected an electrical short circuit to the battery voltage (power) on the low-side circuit of the fuel injector cable for Cylinder 3.

• New Holland T7 Series (T7.220, T7.235, T7.250, T7.260, T7.270)
• New Holland T8 Series (T8.xxx)
• New Holland B110B Backhoe Loaders
• New Holland W-Series Wheel Loaders (W50C, W60C, W70C, W80C)

1. 1

   Inspect the engine wiring harness routing from the Engine ECU to the Cylinder 3 injector for rubbed-through insulation, pinched wires, or chafing against the engine block.

2. 2

   Check the pass-through connector at the valve cover (if applicable) for oil intrusion, melted pins, or damaged wires.

3. 3

   Disconnect the harness at the ECU and at the Cylinder 3 injector, then test the low-side wire of the Cylinder 3 circuit for continuity to the positive battery terminal or a 12V source.

4. 4

   Test the resistance across the pins of the Cylinder 3 injector itself and compare the reading to the other functioning injectors to check for an internal short.

1. 1

   Disconnect Power

   Turn off the machine and disconnect the negative battery cable to prevent ECU damage during testing and repair.

2. 2

   Access the Injector

   Remove the engine covers and, if necessary, the valve cover to access the Cylinder 3 fuel injector and its wiring harness.

3. 3

   Repair or Replace the Harness

   If the diagnostic tests revealed a short in the wiring harness, carefully open the wire loom and repair the damaged section of the wire using proper solder and heat-shrink tubing. If the damage is extensive or located inside the valve cover pass-through, replace the entire injector wiring harness.

4. 4

   Replace the Injector

   If the harness tested good but the injector solenoid failed the resistance test, remove the high-pressure fuel line and hold-down clamp for Cylinder 3. Remove the faulty injector, clean the injector cup, and install a new injector with new O-rings and a new copper crush washer.

5. 5

   Reassembly

   Reconnect the injector harness, reinstall the valve cover (if removed), and reconnect the battery.

6. 6

   Clear Codes

   Connect a diagnostic scan tool to the machine, clear the NH 3069 fault code, and run the engine to verify the repair.