New Holland 3075 – ECM: Cylinder 6 - Injector Cable Short Circuit (High Side To Ground)

The Engine Control Module (ECM) has detected a high-side-to-ground short circuit in the fuel injector cable for cylinder 6. This indicates that the positive voltage wire in the injector's electrical circuit has improperly connected to the chassis or another ground point. This condition disrupts the power supply, preventing the injector from opening and closing correctly, which can lead to engine misfires, rough running, and reduced power.

• T6030
• T6050
• T6070
• T6080
• T6090
• T1804B
• T7.175
• T7.190
• T7.230
• T7.245
• T7.270
• T7.290

1. 1

   Confirm the fault by checking if code 3075 is active. Note the number of occurrences and the engine hours at which it was logged, then clear the code and operate the machine to see if it returns (to rule out an intermittent issue)

2. 2

   Visually inspect the engine wiring harness leading to the cylinder 6 injector for chafing, melting, or pinched wires that could cause a short to the engine block

3. 3

   Inspect the main engine controller connector (Connector A, specifically pins 2 and 15) and the cylinder 6 injector connector for corrosion, damage, or backed-out pins. Clean the connections and ensure they are fully seated upon reconnection

4. 4

   Test the injector circuit integrity between the controller and the injector using a harness diagnostic kit (e.g., CNH tool 380040185) and an injector test fixture

5. 5

   Test the cylinder 6 injector for internal shorts, or swap it with an injector from another cylinder to see if the fault follows the injector

1. 1

   Disconnect battery

   Disconnect the negative battery terminal before beginning any electrical or fuel system repairs.

2. 2

   Repair wiring harness

   If wiring damage is found, isolate and repair the wire using an approved splicing method with heat-shrink tubing. If damage is extensive, replace the entire engine or injector harness. Secure the harness away from sharp edges, hot exhaust components, and moving parts.

3. 3

   Access the injector

   If diagnostics point to a faulty injector, thoroughly clean the area around the valve cover and cylinder 6 injector. Remove the engine valve cover and any obstructing components such as high-pressure fuel lines.

4. 4

   Remove faulty injector

   Disconnect the electrical connector and high-pressure fuel line (using a backup wrench to prevent stressing fittings). Cap the open fuel line and injector port immediately. Loosen the hold-down clamp and carefully twist and pull the injector out of its bore. Avoid excessive force; specialized pullers may be required if the injector is seized.

5. 5

   Install new injector

   Ensure the injector bore is clean. Install the new injector using a new copper crush washer and O-rings, ensuring it is correctly oriented. Tighten the hold-down clamp to the manufacturer's specified torque to prevent fuel leaks.

6. 6

   Reassemble and test

   Reconnect the fuel line and electrical connector. Reinstall the valve cover with a new gasket. Reconnect the battery, prime the fuel system to bleed air, start the engine, and check for leaks. Use a diagnostic tool to clear any fault codes. Perform an injector reset/coding with a diagnostic tool if required by the ECU.