Case IH 486 – Engine Controller (ENG) / Engine Control Module (ECM): Rear Fueling actuator underfueling

The Engine Control Module (ECM) has detected that the fuel pressure in the rear fueling actuator circuit is lower than the commanded pressure. The actuator is failing to deliver the expected volume of fuel to the rear bank of cylinders, which can lead to rough idling, hesitation, stalling, or a failure to start.

• MX Magnum
• STX Steiger
• Steiger series tractors
• Magnum series tractors (e.g., 215, 245, 275, 305, 335, 420)
• Axial-Flow Combines (e.g., 7150, 9250)

1. 1

   Monitor fuel filter restriction live data for a clogged fuel filter starving the high-pressure pump.

2. 2

   Inspect the fuel tank and water separator for contamination (algae, water, or debris) restricting flow.

3. 3

   Inspect the injector/actuator wiring harness leading to the rear fueling actuator for open circuits, shorts to ground, or corroded connectors.

4. 4

   Perform a leak test on the rear fueling actuator base to check for blown O-rings or internal leaks.

1. 1

   Replace Filters

   Drain the water separator and replace both the primary and secondary fuel filters (do not skip the secondary filter). Clear the code and run the engine to see if the restriction is resolved.

2. 2

   Harness Repair

   If the filters are clean but the code persists, disconnect the battery and test the rear fueling actuator harness. Repair or replace the harness if voltage/continuity tests fail.

3. 3

   Actuator Replacement

   If the fuel supply and wiring are verified as good, the rear fueling actuator itself has likely failed mechanically.

4. 4

   Clean mounting surface

   Clean the fuel control housing mounting surface.

5. 5

   Remove faulty actuator

   Remove the mounting bolts securing the faulty rear fueling actuator.

6. 6

   Install new actuator

   Install the new rear fueling actuator using the new seals/O-rings provided in the replacement kit.

7. 7

   Torque bolts

   Torque the mounting bolts to OEM specifications.

8. 8

   Verify repair

   Prime the fuel system, start the engine, and run it through multiple operating cycles to verify the permanent code clears from the ECM.