Fendt 1.2.64 – A051 - ECU, engine control unit (EDC 7): Misfiring on cylinder 4

Misfiring on cylinder 4 (SERDIA Fault Code: 0029).

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 300 Vario COM III
• Fendt 400 Vario COM III (409, 410, 412)
• Fendt 700 Vario COM III (712, 714, 716, 718)
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III (919, 922, 925, 928, 931, 934, 936)

1. 1

   Connect the SERDIA diagnostic software to the tractor to confirm the active fault (FC:0029) and check for any related fuel pressure or electrical codes.

2. 2

   Inspect the wiring harness running from the A051 Engine Control Unit (EDC 7) to the cylinder 4 fuel injector. Look for chafing, breaks, or loose connector pins that could interrupt the signal.

3. 3

   Perform a cylinder cutout test using the diagnostic tool to verify that cylinder 4 is the dead cylinder.

4. 4

   If the electrical circuit is intact, perform a compression test on cylinder 4 to rule out mechanical engine failure (e.g., worn piston rings or valve issues).

1. 1

   Isolate the Fault

   If the wiring harness is damaged, repair or replace the affected section of the harness.

2. 2

   Replace the Injector

   If the wiring and engine compression are good, the fuel injector for cylinder 4 is likely faulty and must be replaced. Depressurize the fuel system, remove the valve cover/injector lines, extract the faulty injector, and install the new injector with new O-rings and sealing washers. Torque all hold-down bolts and fuel lines to the manufacturer's specifications.

3. 3

   Clear Codes

   Reconnect the SERDIA diagnostic tool and delete the error code (FC:0029) from the EDC 7 memory.

4. 4

   Test Run

   Start the engine and verify that it runs smoothly without misfires. Ensure the fault code does not return under load.