Case IH 3303 – Engine ECU: Cylinder 4 Specific Errors - No Signal

The engine controller is not detecting an electrical signal from the fuel injector solenoid on cylinder 4. The underlying condition is typically an open circuit, a disconnected wiring harness, or an internal failure of the injector solenoid itself.

• Magnum 235
• Magnum 250
• Magnum 260
• Magnum 280
• Magnum 290
• Magnum 310
• Magnum 315
• Magnum 340
• Magnum 370
• Magnum 380
• Steiger 350
• Steiger 370
• Puma series
• Maxxum series
• Combine 6130
• Combine 7130
• Combine 7230
• Combine 8230
• Combine 9230
• Patriot 4430
• Patriot 4440
• Titan series

1. 1

   Visually inspect the cabling and connections running from the engine controller to the cylinder 4 fuel injector

2. 2

   Inspect the cylinder 4 injector connector for disconnected, loose, pushed-back, or corroded pins

3. 3

   Use a multimeter to check for harness continuity, looking for an open circuit or a short in the wiring between the Engine ECU and the cylinder 4 injector

4. 4

   Measure the solenoid resistance across the pins of the cylinder 4 injector (an infinite resistance reading confirms the solenoid has failed internally)

1. 1

   Turn off the machine, remove the key, and disconnect the battery

   Prevents electrical shorts.

2. 2

   Locate the cylinder 4 fuel injector on the engine block

   Typically the 4th cylinder from the front/fan side.

3. 3

   Disconnect the electrical pigtail from the cylinder 4 injector

4. 4

   Inspect the harness side of the connector

   If the wires are chafed, broken, or melted, splice in a new injector connector pigtail or replace the damaged harness section.

5. 5

   Determine if the injector solenoid has failed

   If the wiring is intact and continuity to the ECU is good, the injector solenoid has failed.

6. 6

   Clean the area around the injector

   Prevents debris from entering the cylinder.

7. 7

   Remove the high-pressure fuel line connected to the cylinder 4 injector

8. 8

   Remove the injector hold-down clamp and extract the faulty injector

9. 9

   Install the new replacement injector

   Use new O-rings and a new copper sealing washer.

10. 10

    Reinstall the hold-down clamp

    Torque to OEM specifications.

11. 11

    Reconnect the high-pressure fuel line and the electrical connector

12. 12

    Reconnect the battery, clear the fault codes, and run the engine

    Clear codes via the diagnostic menu or scan tool, verify the repair, and check for fuel leaks.