New Holland ENG 3077 – Engine Controller (EDC / Engine ECU): Cylinder 2 - Injector Cable Short circuit (Low Side to Battery)

The engine control system has detected a short circuit to battery voltage on the low-side circuit of the fuel injector wiring for cylinder number 2.

• T8 Series (T8.275 through T8.435)
• T9 Series (T9.390, T9.435)
• T7 Series
• T6000/T7000 series
• CR7.90
• CR8.90
• CR9.90
• W190B Wheel Loaders
• Case 1021F
• Case 1121F
• Magnum 235-340 (Series 4)
• Puma
• Maxxum series

1. 1

   Inspect the engine wiring harness leading to the Cylinder 2 injector for chafed insulation, melted wires, or rubbing against the engine block.

2. 2

   Measure the resistance of the Cylinder 2 injector solenoid coil (should be 0.4 to 0.5 ohms).

3. 3

   Test the low-side wire of the disconnected harness for continuity to battery positive to isolate harness shorts.

4. 4

   Check the Engine ECU (EDC) connector pins for corrosion, moisture ingress, or bent pins.

1. 1

   Disconnect Power

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

2. 2

   Access the Injector

   Remove any engine covers or valve covers necessary to access the Cylinder 2 fuel injector and its wiring harness.

3. 3

   Isolate the Fault

   Based on the diagnostic checks, determine if the short is in the wiring harness or internal to the injector solenoid.

4. 4

   Repair/Replace Wiring (If Applicable)

   If the harness is shorted, carefully splice and repair the damaged section of the wire using heat-shrink connectors, or replace the entire injector wiring harness if the damage is extensive or internal to a molded connector.

5. 5

   Replace the Injector (If Applicable)

   If the injector solenoid is internally shorted to power, remove the high-pressure fuel line and the injector hold-down clamp. Extract the faulty injector and install a new one. Note: New common-rail injectors often require programming/coding the new injector's calibration code into the Engine ECU using a diagnostic tool.

6. 6

   Reassembly

   Reconnect the injector harness, reinstall the valve cover (if removed), and reattach the high-pressure fuel lines.

7. 7

   Clear Codes

   Reconnect the battery. Use a diagnostic tool or CAN-Bus emulator to clear the inactive ENG 3077 fault code from the Engine ECU.

8. 8

   Test Run

   Start the engine and verify that it runs smoothly without misfires and that the fault code does not return.