Case IH 3298 – Engine Control Unit (ECU) / Bosch EDC7: Cylinder 2 Specific Errors - Signal Not Plausible

The Engine Control Unit (ECU) has detected an irregular, missing, or illogical electrical signal from the fuel injector on cylinder number 2. This typically points to an electrical fault within the injector's internal solenoid, a wiring harness issue (such as a short circuit or open circuit), or a poor connection that is preventing the ECU from properly controlling or monitoring the injector's firing event.

• Magnum 235
• Magnum 260
• Magnum 290
• Magnum 315
• Magnum 340 (Series 4)
• Puma Series

1. 1

   Visually inspect the wiring harness running from the Engine ECU to the Cylinder 2 fuel injector for chafing, melted insulation, or pinched wires.

2. 2

   Disconnect the Cylinder 2 injector connector and the ECU harness connector to inspect for corrosion, moisture, backed-out pins, or loose terminals.

3. 3

   Measure the resistance of the Cylinder 2 injector solenoid directly at the injector pins using a multimeter and compare to a known good injector or OEM specification.

4. 4

   Check the injector circuit wires for continuity from the ECU connector to the injector connector, and test for shorts to ground or battery voltage.

5. 5

   Connect a diagnostic scanner to perform an Injector Deactivation or Cylinder Cut-out test while the engine is running to verify Cylinder 2 contribution.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the negative battery cable to prevent electrical spikes.

2. 2

   Access the Injector

   Remove the engine valve cover or injector harness cover as required by the specific engine model to access the Cylinder 2 injector.

3. 3

   Repair Wiring

   If the diagnostic tests revealed a wiring fault, repair the damaged section of the harness or replace the injector pigtail connector. Use heat-shrink butt connectors to ensure a weather-tight seal.

4. 4

   Replace the Injector

   If the injector solenoid failed the resistance test or the cylinder cut-out test, remove the high-pressure fuel line and the injector hold-down clamp. Extract the faulty Cylinder 2 injector.

5. 5

   Install New Injector

   Clean the injector bore in the cylinder head. Install the new injector with a new copper sealing washer and O-rings. Torque the hold-down clamp and high-pressure fuel lines to OEM specifications.

6. 6

   Reassembly

   Reconnect the injector electrical connector. Reinstall the valve cover and any other removed components.

7. 7

   ECU Programming

   If a new injector was installed, use the diagnostic tool to program the new injector's calibration code (IQA/IMA code) into the Engine ECU so it can adjust the fueling map properly.

8. 8

   Clear Codes and Test

   Reconnect the battery, clear the 3298 fault code using the diagnostic tool, and run the engine to verify the repair and check for fuel leaks.