Fendt 1.2.BA – A051 - ECU, engine control unit (EDC 7): CAN-message missing

The tractor's communication network is failing to receive expected CAN bus messages from or to the engine control unit. In the SERDIA diagnostic software, this specific fault is often accompanied by the internal failure code FC:007A.

• 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 900 Vario (COM III)

1. 1

   Connect the Fendt SERDIA diagnostic software to confirm the fault code (FC:007A).

2. 2

   Refer to the 'EDC engine control' circuit diagram (specifically Sheet 36 in the OEM manual) to trace the CAN bus lines.

3. 3

   Inspect the CAN bus wiring harness connecting to the A051 Engine Control Unit for physical damage, chafing, or breaks.

4. 4

   Check the communication lines between the A051 (Engine ECU) and the A002 (Enhanced Control ECU), as CAN connection faults between these two modules are a common cause.

5. 5

   Inspect the A051 ECU connectors for corrosion, moisture ingress, or loose pins.

1. 1

   Disconnect battery

   Disconnect the tractor's battery power before servicing the ECU or wiring harness.

2. 2

   Repair or replace wiring

   Repair or replace any damaged sections of the CAN bus wiring harness identified during the diagnostic checks.

3. 3

   Clean connectors

   Clean the connector pins on the A051 Engine Control Unit and securely reconnect the harness.

4. 4

   Perform EOL programming

   If the wiring and connections are verified as fully functional, the A051 ECU may have a software corruption issue. Perform an EOL (End of Line) programming with a new data record using the dealer diagnostic tool.

5. 5

   Replace ECU

   If EOL programming fails or the module is internally shorted, replace the A051 Engine Control Unit (EDC 7).

6. 6

   Delete error code

   Reconnect battery power and use the SERDIA diagnostic software to delete the error code.

7. 7

   Verify repair

   Run the tractor to verify that CAN communication is restored and the fault does not return.