Case IH 3808 (F-1240-14) - ECU – Engine Control Unit (ECU) / Electronic Diesel Control (EDC): High pressure pump fuel delivery quantity at low idle is too high.

The engine control system detects that the high-pressure fuel pump is delivering a volume of fuel that exceeds the maximum allowable threshold while the engine is operating at low idle. This typically indicates that the Fuel Metering Unit (FCA/MPROP) is sticky, stuck, or failing to properly regulate the fuel flow to the pumping plungers, or a skewed fuel rail pressure sensor is providing inaccurate feedback.

• VESTRUM CVX
• 240 Series Axial-Flow Combines
• Magnum Tractors (MX210, MX230, MX255, MX285)
• Farmall Tractors (40, 45, 50)
• Puma Series Tractors
• Maxxum Series Tractors (110, 115, 120, 125, 130, 140)
• MTA CCM & APH Stage V MR machines

1. 1

   Check for related codes (e.g., 3810 or 3112) using the Case IH Electronic Service Tool (EST) to rule out electrical or sensor-related issues.

2. 2

   Verify the tractor battery power supply has not been connected to an external power supply; disconnect if present and retest.

3. 3

   Check battery voltage on the instrument cluster with the engine running at 2000 RPM to ensure stable voltage to the ECU and sensors.

4. 4

   Perform an FCA Unplug Test: unplug the Fuel Control Actuator to eliminate metering. If engine behavior changes drastically or starts, the FCA is likely the culprit.

1. 1

   Turn off machine and disconnect battery

   Turn off the machine, remove the key, and disconnect the battery to prevent electrical shorts and ensure safety while working on the fuel system.

2. 2

   Locate high-pressure fuel pump and FCA

   Locate the high-pressure fuel pump (typically a Bosch CP3 pump) on the engine. The Fuel Metering Unit / FCA is mounted directly to the back or side of this pump.

3. 3

   Disconnect and inspect electrical harness

   Disconnect the electrical wiring harness from the FCA. Inspect the connector pins for corrosion, pushed-out pins, or wire chafing.

4. 4

   Clean area around FCA

   Thoroughly clean the area around the FCA to prevent any dirt or debris from entering the high-pressure fuel pump during removal.

5. 5

   Remove FCA mounting screws

   Remove the mounting screws (usually T25 Torx or Allen head) securing the FCA to the pump.

6. 6

   Remove old FCA

   Carefully pull the old FCA out of the pump housing.

7. 7

   Lubricate new FCA O-rings

   Lubricate the O-rings on the new FCA with clean diesel fuel to prevent tearing during installation.

8. 8

   Install new FCA

   Insert the new FCA into the pump housing and tighten the mounting screws to the OEM torque specification.

9. 9

   Reconnect electrical harness

   Reconnect the electrical harness to the FCA.

10. 10

    Reconnect battery and prime system

    Reconnect the battery. Turn the key to the ON position to allow the lift pump to prime the system.

11. 11

    Clear fault codes

    Connect the Case IH EST (Electronic Service Tool) to clear the 3808 fault code and any associated limp-mode resets.

12. 12

    Verify repair

    Start the engine and monitor the actual vs. desired fuel rail pressure at low idle to verify the repair.