New Holland ENG 3071 – Engine Control Unit (ECU) / EDC7: Cylinder3 - Injector Cable Short Circuit (High Side to Ground)

The engine's control system has detected a direct short to ground on the high-voltage (supply) side of the electrical circuit for the fuel injector on cylinder number 3, resulting in a cylinder misfire, rough running, and a loss of engine power.

• T8.320
• T8.350
• T8.380
• T8010
• B95B
• B100B
• B110B
• B115B
• D85B
• D95B
• CR9090
• CX8080 Elevation
• CX8090 Elevation
• Magnum 235-340

1. 1

   Visually inspect the engine wiring harness routing from the EDC7 controller to the cylinder 3 injector for chafing, melted wire insulation, or pinch points against the engine block or valve cover.

2. 2

   Disconnect the injector harness from the EDC7 controller and use a multimeter to check for continuity between the high-side pin for cylinder 3 (Pin 6 and Pin 5) and the engine ground. Continuity indicates a short in the wiring.

3. 3

   Disconnect the electrical connector directly at the cylinder 3 fuel injector and test for continuity between the injector pins and the injector body. Continuity to the body indicates the short is internal to the injector.

4. 4

   Inspect the EDC7 ECU pins for corrosion, moisture ingress, or bent terminals that could be bridging the circuit to a ground pin.

1. 1

   Power Down

   Turn off the machine and disconnect the battery via the master disconnect switch to prevent electrical arcing or ECU damage.

2. 2

   Access the Injector

   Remove any necessary engine covers or the valve cover (depending on the engine model) to access the cylinder 3 fuel injector and its wiring.

3. 3

   Isolate the Fault

   Based on the diagnostic checks, determine if the short is in the wiring harness or internal to the injector itself.

4. 4

   Repair/Replace Wiring

   If the harness is shorted, locate the damaged section. Repair the wire using proper soldering and heat-shrink tubing, or replace the entire engine injector wiring harness if the damage is extensive or internal to a molded loom. If the connector at the ECU is damaged, an EDC7 89-way ECU repair harness loom can be spliced in.

5. 5

   Replace the Injector

   If the short is internal to the injector, clean the area around the injector. Remove the high-pressure fuel line and the injector retaining clamp. Extract the cylinder 3 fuel injector and install the replacement.

6. 6

   Reassembly

   Reconnect the injector electrical connector, fuel lines, and the EDC7 harness.

7. 7

   Clear Codes

   Reconnect the battery. Connect the New Holland EST (Electronic Service Tool) diagnostic software to the machine, clear the stored ENG 3071 fault code, and run the engine to verify the misfire and code do not return.