New Holland ENG 3079 – Engine Control Unit (ECU) / EDC / EDC7: Cylinder 2 - Injector Cable Short Circuit (High Side to Ground)

The engine controller has detected a short circuit to ground on the high-voltage (supply) side of the electrical circuit for the fuel injector on cylinder number 2. This prevents the injector from firing properly, leading to a misfire, rough running, and loss of power.

• New Holland T5 series (T5.95, T5.105, T5.115)
• New Holland T6 series
• New Holland T7 series (T7.165 to T7.270)
• New Holland T8 series (T8.275 to T8.435)
• New Holland T9 series
• New Holland CR9090
• New Holland CX8080
• New Holland CX8090

1. 1

   Multimeter Requirements: You must use a high-quality Digital Multi-Meter (DMM) capable of measuring resistance to a resolution of 0.1 ohms. Inaccuracies in the DMM can lead to incorrect diagnoses.

2. 2

   Coil Resistance Test: Measure the resistance of the cylinder 2 injector solenoid coil. A healthy injector solenoid coil typically reads between 0.4 and 0.5 ohms.

3. 3

   Harness Inspection: Inspect the wiring harness connecting the engine controller to the cylinder 2 fuel injector. Look for areas where the harness may be rubbing against the engine block or brackets, causing the insulation to chafe and short to ground.

4. 4

   Continuity to Ground Test: Disconnect the injector and the engine controller. Test the high-side wire of the cylinder 2 injector circuit for continuity to ground. If continuity exists, the short is in the wiring harness. If the harness tests open to ground, the short is likely internal to the injector solenoid.

1. 1

   Isolate the Short

   Based on the diagnostic checks, determine if the short to ground is located in the engine wiring harness or inside the fuel injector solenoid.

2. 2

   Repair the Harness

   If the harness is chafed or melted, repair the damaged section of the wire and reinforce it with loom/heat-shrink, or replace the entire injector wiring harness section if the damage is extensive.

3. 3

   Replace the Injector

   If the harness tests perfectly fine but the injector solenoid fails the resistance test or is internally shorted to its casing, replace the cylinder 2 fuel injector.

4. 4

   Clear Codes and Retest

   After the repair is made, use approved diagnostic equipment (such as the CNH Electronic Service Tool) to clear the ENG 3079 error code.

5. 5

   Validation

   Run the machine under normal operating conditions and retest to ensure the fault code does not return and the cylinder is firing correctly.