New Holland ENG 3078 – Engine ECU: Cylinder2 - Application Dependent

This fault code indicates an electrical issue specific to the fuel injector on Cylinder 2. The ECU detects that the injector is not responding correctly to the commanded electrical pulse, which could be an unclassifiable injector circuit error such as an open load, a current level error, or a fast decay error in the injector solenoid.

• New Holland T8 Series (T8.275, T8.300, T8.330, T8.360, T8.390, T8.410, T8.420, T8.435)
• New Holland T9 Series
• Axial-Flow combines
• Patriot/Miller sprayers

1. 1

   Inspect the wiring harness from the Engine ECU to the Cylinder 2 injector for chafing, melted wires, or pinch points that could cause an open circuit or high resistance.

2. 2

   Disconnect the Cylinder 2 injector connector and the main ECU harness connectors to check for pushed-back pins, corrosion, or moisture intrusion.

3. 3

   Using a multimeter, measure the resistance across the pins of the Cylinder 2 injector solenoid and compare the reading to a known good injector (an open circuit or dead short indicates a failed injector solenoid).

4. 4

   Check for continuity between the injector connector and the corresponding pins on the ECU to rule out a broken wire.

1. 1

   Preparation

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts. Clean the area around the Cylinder 2 injector thoroughly to prevent dirt from entering the engine.

2. 2

   Remove Fuel Lines

   Loosen and remove the high-pressure fuel injection line connected to Cylinder 2. Cap all open fuel ports immediately to prevent contamination.

3. 3

   Disconnect Wiring

   Unplug the electrical connector from the Cylinder 2 injector.

4. 4

   Extract the Injector

   Remove the injector hold-down clamp bolt and carefully extract the injector from the cylinder head.

5. 5

   Install New Injector

   Lubricate the new injector O-rings/sealing rings with clean engine oil. Seat the new injector into the cylinder head and install the hold-down clamp. Torque the clamp bolt to the exact OEM specification.

6. 6

   Reassemble

   Reinstall the high-pressure fuel line (it is highly recommended by OEM standards to replace the high-pressure line whenever it is removed). Torque the line fittings to spec. Reconnect the electrical harness.

7. 7

   Calibration & Clearing

   Reconnect the battery. Use the CNH Electronic Service Tool (EST) to clear the ENG 3078 fault code. Program the new injector's specific trim code (IQA code) into the Engine ECU for proper fueling and emissions compliance.

8. 8

   Test Run

   Prime the fuel system, start the engine, and check for leaks. Verify that the engine runs smoothly and the code does not return.