Case IH 3077 – Engine Controller (EDC / Engine ECU): Cylinder 2 - Injector Cable Short-circuit (Low Side to Battery)

The control module has detected an electrical short to a battery voltage source on the low side (the ground or return circuit) of the wiring harness leading to the fuel injector on cylinder #2.

• Case IH Magnum Series (e.g., 215, 235, 245, 340)
• Case IH Puma Series (e.g., 165, 180, 195, 210, 225 CVX)
• Case IH Steiger Series
• Case IH Maxxum Series

1. 1

   Visually inspect the engine wiring harness leading to the cylinder 2 injector for obvious signs of chafing, melted insulation, or pinched wires

2. 2

   Disconnect the harness at the Engine ECU and at the cylinder 2 fuel injector to check the pins for corrosion, moisture, or damage

3. 3

   With both ends disconnected, use a multimeter to test the low-side wire of the cylinder 2 injector circuit for continuity to battery voltage to identify a harness short

4. 4

   Ohm test the cylinder 2 fuel injector itself to rule out an internal short inside the injector solenoid

1. 1

   Disconnect Power

   Ensure the ignition is off and the main battery disconnect switch is turned off.

2. 2

   Access the Injector

   Remove any engine covers or valve covers necessary to access the cylinder 2 fuel injector and its wiring harness.

3. 3

   Repair or Replace Wiring

   If the diagnostic tests revealed a short in the harness, locate the damaged section. Depending on the severity, either repair the wire using OEM-approved splicing methods or replace the entire engine injector wiring harness.

4. 4

   Replace the Injector (If Faulty)

   If the injector solenoid tested as internally shorted, remove the high-pressure fuel line connected to cylinder 2. Remove the hold-down clamp and extract the faulty injector. Install the new injector with new O-rings/seals.

5. 5

   Reinstall Fuel Lines

   Reinstall the high-pressure fuel line. (Note: High-pressure metal injection lines are often single-use and should be replaced if removed, per standard common-rail diesel procedures).

6. 6

   Reassembly and Testing

   Reconnect the injector harness and the Engine ECU. Reconnect the battery. Use a diagnostic scan tool to clear the 3077 fault code, then start the engine and verify that the code does not return and the engine runs smoothly.