Case IH 3221 (F-2798-04) - ECU – Engine Control Unit (ECU): Short Circuit to Ground Monitoring Test in Bank 2

Indicates an electrical malfunction—specifically a short circuit to ground or an unclassified electrical anomaly—in the fuel injector wiring harness for Bank 2.

• VESTRUM CVX
• Magnum Series (235 - 340)
• Steiger Series (350 - 600)
• Puma Series (165 - 225)
• Farmall Series (85C - 115C)
• Patriot Sprayers (3240, 3340)

1. 1

   Inspect the Bank 2 fuel injector wiring harness for chafing, melted insulation, or pinched wires that could cause a short to ground.

2. 2

   Disconnect the Bank 2 injectors and test their resistance. A healthy injector solenoid should read less than 1 ohm but greater than 0 ohms. A reading of 0 ohms indicates a dead short inside the injector.

3. 3

   Disconnect the harness from the ECU and the injectors. Check for continuity between the injector signal wires and the engine block (ground). There should be no continuity.

4. 4

   Inspect the ECU connector pins for corrosion, moisture, or bent pins that could bridge a connection to ground.

1. 1

   Disconnect power

   Turn off the battery disconnect switch to prevent electrical arcing.

2. 2

   Repair or replace wiring

   If the harness continuity test reveals a short to ground, trace the harness to the exact point of failure. Repair the chafed wire using approved heat-shrink butt connectors, or replace the entire Bank 2 injector wiring harness.

3. 3

   Replace faulty injector

   If an individual injector failed the resistance test (internal short), remove the valve cover (if applicable), remove the injector hold-down clamp, and replace the faulty injector. Torque all fittings to OEM specifications.

4. 4

   Replace the ECU

   If the wiring and injection signals test perfectly fine, the defect is an internal ECU hardware failure. You must replace the Engine Control Unit.

5. 5

   Clear and retest

   Reconnect all components, restore battery power, and use the Electronic Service Tool (EST) to clear the fault codes. Run the engine to verify the code does not return.