Case IH 3851 – Engine Control Unit (ECU / EDC): ENGINE, Injector - Zero Fuel Calibration by Lambda (ZFL): DFC reporting error state on comparing energizing time to Minimum value injector 4.

The Engine Control Unit (ECU) periodically performs a "Zero Fuel Calibration" using the exhaust lambda (oxygen) sensor to monitor fuel delivery. This code sets when the ECU detects that the electrical energizing time required to operate Injector #4 has fallen below the minimum allowable threshold. This typically indicates that the injector is mechanically leaking, has an internal defect, or the injector's calibration code (IMA code) programmed into the ECU is incorrect.

• skid steer
• SR210
• SR220
• SR240
• SR250
• SR270
• SV250
• SV280
• SV300
• SV340
• TR270
• TR310
• TR320
• TR340
• TV370
• TV380
• Farmall 65C
• Farmall 75C
• Farmall 80N
• Farmall 90V
• Farmall 100N
• Farmall 110V

1. 1

   Verify Injector Programming: Using the Electronic Service Tool (EST) / Easy-Engine software, verify that the 9-digit IMA calibration code stamped on the physical Injector #4 matches the code programmed into the ECU for cylinder 4.

2. 2

   Inspect Wiring: Disconnect the engine harness from Injector #4 and the ECU. Inspect all connectors, pins, and the wiring harness for corrosion, bent pins, or wire breaks.

3. 3

   Check for Leaks: Inspect the high-pressure fuel lines and the injector body for any signs of external fuel leakage.

1. 1

   Depressurize

   Ensure the engine is off and the high-pressure fuel system is completely depressurized before opening any lines.

2. 2

   Disconnect

   Disconnect the electrical harness connector from Injector #4.

3. 3

   Remove Fuel Line

   Loosen and remove the high-pressure fuel line connecting the fuel rail to Injector #4. Cap the rail fitting to prevent contamination.

4. 4

   Remove Injector

   Remove the injector hold-down clamp/bolt and carefully extract the faulty injector from the cylinder head.

5. 5

   Clean

   Thoroughly clean the injector bore in the cylinder head, ensuring no old copper washer material or carbon buildup remains.

6. 6

   Install New Injector

   Install the new injector using a new copper sealing washer and O-ring.

7. 7

   Reassemble

   Reinstall the hold-down clamp and torque to OEM specifications. Reconnect the high-pressure fuel line and torque to spec. Reconnect the electrical harness.

8. 8

   Program ECU

   You must use the EST diagnostic software to program the new injector's 9-digit IMA code into the Engine ECU for cylinder 4.

9. 9

   Finalize

   Prime the fuel system, start the engine, check for leaks, and clear the fault codes.