Fendt 1.2.61 – A051 - ECU, engine control unit (EDC 7): Misfiring on cylinder 1

The engine control system has detected that the first cylinder is not firing correctly, which can lead to a loss of power, rough running, or the engine entering a restricted operating mode.

• 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
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 820 Vario greentec COM III
• Fendt 900 Vario COM III

1. 1

   Read Codes: Connect the AGCO CANUSB Diagnostic Tool and use the SERDIA or Fendias diagnostic software to confirm the active fault code (FC:0026 is often associated with this specific misfire).

2. 2

   Wiring Inspection: Check the wiring harness leading to Injector 1 (Component Y095). Look for a broken wire or a short circuit to the injector, which is a primary cause of misfire codes on these engines.

3. 3

   Component Testing: Test the cylinder 1 fuel injector for proper electrical resistance and mechanical operation.

4. 4

   ECU Verification: If the wiring and injector test perfectly, the fault may lie within the Bosch EDC7UC31 control unit itself, which is known to occasionally suffer from internal hardware faults preventing injector firing.

1. 1

   Safety First

   Turn off the tractor, disconnect the battery, and ensure the engine is cool before working on the fuel system.

2. 2

   Inspect and Repair Wiring

   If the diagnostic checks revealed a short or break in the harness to Injector 1 (Y095), repair or replace the damaged section of the wiring harness.

3. 3

   Replace the Injector

   If the wiring is intact but the injector is faulty, remove the valve cover/injector lines as per the Deutz/Fendt engine manual, extract the faulty cylinder 1 injector, and install a genuine OEM replacement.

4. 4

   ECU Repair/Replacement

   If both the injector and wiring are fully functional, the A051 (EDC 7) ECU must be removed and sent to a specialized mechatronics repair facility (like Ilgenfritz Mechatronics) for internal circuit repair, or replaced entirely.

5. 5

   Clear Codes

   Reconnect the battery, connect the SERDIA/Fendias diagnostic tool, and execute the "delete error" command to clear code 1.2.61 from the A051 ECU memory.

6. 6

   Test Run

   Start the tractor and monitor the engine parameters via the diagnostic tool to ensure the misfire on cylinder 1 has been resolved.