New Holland NH 3078 – Engine Control Unit (ECU) / EDC: Injector solenoid valve Cylinder 2 - SOURCE LOW

The engine's control module has detected a low voltage condition on the circuit operating the fuel injector for cylinder 2. This is typically caused by a short circuit to ground on the low side of the injector cable, an open circuit, or an internal short/failure within the cylinder 2 injector solenoid itself.

• New Holland T8.xxx Series Tractors
• New Holland W270B Wheel Loaders
• Various other New Holland machines utilizing FPT NEF or Cursor engines

1. 1

   Inspect the wiring harness connecting the ECU to the cylinder 2 injector for visible damage, chafing, or melted insulation

2. 2

   Inspect the connectors at both the cylinder 2 injector and the ECU for corrosion, bent pins, or moisture ingress

3. 3

   Disconnect the cylinder 2 injector and measure the resistance of the injector coil using a multimeter (normal resistance for standard FPT NEF engines is 0.56 to 0.57 ohms)

4. 4

   Test the wiring harness for continuity between the ECU connector and the injector connector, and test the wires for a short to ground

1. 1

   Disconnect Power

   Disconnect the machine's battery to prevent electrical damage or accidental shorting during the repair.

2. 2

   Access the Injector

   Remove any necessary engine covers or valve covers to gain access to the cylinder 2 fuel injector.

3. 3

   Address Wiring Issues

   If the diagnostic tests revealed a short to ground in the harness, locate the damaged section of the wire and repair it using proper splicing techniques, or replace the entire injector wiring harness.

4. 4

   Replace the Injector

   If the injector coil failed the resistance test: Disconnect the high-pressure fuel line connected to cylinder 2. Remove the injector hold-down clamp. Extract the faulty injector. Clean the injector cup/bore in the cylinder head. Install the new injector using new sealing washers and O-rings. Reinstall the hold-down clamp and torque to OEM specifications. Reconnect the high-pressure fuel line and electrical connector.

5. 5

   ECU Replacement

   If the wiring harness and the injector both test perfectly, the internal injector driver within the ECU has likely failed. The ECU will need to be replaced and programmed by a dealer.

6. 6

   Reassembly and Clearing Codes

   Reconnect the battery. Use a diagnostic service tool (such as the CNH EASy tool or Jaltest) to clear the inactive NH 3078 fault code from the ECU memory. Run the engine to verify the repair.