New Holland ENG 3069 – Engine ECU: Cylinder 3 - Injector Cable Short circuit (Low Side to Battery)

This indicates an electrical fault where the low side (ground/return side) of the wiring circuit for the cylinder 3 fuel injector is shorted to a battery voltage source. When this occurs, the engine control module cannot properly pulse the injector, which typically results in the ECU shutting down that specific injector to protect the circuit, leading to a misfire, rough running, and loss of power.

• T5 Series
• T6 Series
• T7 Series
• T8 Series
• T9 Series
• T7.210
• T8.390
• CR Series
• CX Series
• CR7.90
• CX8.90
• FR Forage Harvesters
• B110B Tractor Loader Backhoes
• Wheel Loaders (W110C-W190C)
• Skid Steers

1. 1

   Visual Inspection: Inspect the engine wiring harness routing from the Engine ECU to the cylinder 3 fuel injector. Look for areas where the harness may have rubbed against the engine block, brackets, or other components, causing the insulation to chafe and expose bare wire to a power source.

2. 2

   Harness Isolation Test: Disconnect the wiring harness at the Engine ECU and at the cylinder 3 injector. Using a digital multimeter, test for continuity between the low-side pin of the cylinder 3 injector connector and the positive battery terminal (or any 12V/24V power supply line). If voltage or continuity is present, the harness is shorted.

3. 3

   Injector Solenoid Test: Test the resistance across the pins of the cylinder 3 fuel injector itself. An internal short inside the injector solenoid can sometimes trigger this code. Compare the resistance reading to a known good injector on an adjacent cylinder.

4. 4

   Connector Check: Inspect the ECU and injector connectors for water intrusion, corrosion, or bent pins that could be bridging the low side to a power circuit.

1. 1

   Disconnect Power

   Disconnect the negative battery cable to prevent any further electrical damage or accidental shorts during the repair.

2. 2

   Access the Injector

   Remove any engine covers or valve covers necessary to access the cylinder 3 fuel injector and its wiring harness.

3. 3

   Address the Wiring Harness

   If the diagnostic tests revealed a short in the wiring harness, carefully unloom the harness at the site of the damage. If the damage is localized, repair the broken insulation using OEM-approved heat-shrink connectors and re-loom the harness securely away from vibration points. If the harness is heavily melted, oil-soaked, or damaged in multiple places, replace the entire engine fuel injector wire harness.

4. 4

   Address the Injector (if faulty)

   If the injector failed the resistance test, remove the high-pressure fuel line and the injector hold-down clamp. Extract the cylinder 3 injector, clean the injector bore, and install a new injector with new copper sealing washers and O-rings.

5. 5

   Reassembly

   Reconnect the wiring harness to the injector and the ECU. Reinstall any removed covers.

6. 6

   Clear Codes and Test

   Reconnect the battery. Use a diagnostic scan tool (like the CNH EST tool) to clear the ENG 3069 fault code. Start the engine and verify that it runs smoothly without throwing the code again. (Note: If a new injector was installed, you may need to program the new injector's IMA calibration code into the Engine ECU using the diagnostic tool).