Fendt 1.2.C2 – A051 - ECU, engine control unit (EDC 7): CAN bus A, break in wiring or short circuit.

The engine control unit has detected a communication failure on CAN bus A due to either a broken wire (open circuit) or a short circuit in the harness. The tractor will typically enter a restricted operating mode, but it remains possible to drive the machine using the foot throttle/accelerator pedal.

• 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 200 Vario V / F / P
• 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 stored fault codes using the tractor's terminal or the SERDIA diagnostic software to confirm the presence of code 1.2.C2 (FC:00C0).

2. 2

   Check battery voltage, as voltage drops or weak batteries commonly destabilize CAN communication and can trigger false ghost signals.

3. 3

   Inspect the CAN bus A wiring harness for physical damage, chafing, or moisture exposure (refer to Fendt electrical wiring diagram Sheet 35).

4. 4

   Check ground resistance and look for fretting corrosion on the EDC 7 connectors, as poor grounding greatly reduces CAN network stability.

1. 1

   Disconnect power

   Disconnect the battery before detaching or reattaching any control unit wiring to prevent voltage spikes.

2. 2

   Access the ECU

   Locate the A051 Engine Control Unit (EDC 7).

3. 3

   Inspect the connector

   Remove the 89-way connector from the ECU. Check for bent pins, water ingress, or oil contamination, which is a common issue on EDC 7 units.

4. 4

   Repair the harness

   If a break or short is found on the CAN bus A lines (per wiring diagram Sheet 35), repair the damaged section of the wiring harness. If the connector itself is heavily corroded, splice in a replacement 89-way pigtail harness.

5. 5

   Reconnect and clear codes

   Reconnect the ECU and the battery. Delete the fault codes using the SERDIA diagnostic software, as codes in the A051 EDC 7 module often cannot be permanently cleared via the dashboard terminal.

6. 6

   Test drive

   Operate the tractor under load to ensure CAN communication remains stable and the fault does not return. If the fault persists despite perfect wiring, the EDC 7 ECU itself may have suffered internal hardware failure and will require cloning or replacement.