Fendt 0.0.15 – ECU, enhanced control (A002): 4WD engagement; Diff. lock engagement (AWD; Differential - Lock activation) - Bus fault.

There is a communication failure on the CAN bus responsible for the 4WD and differential lock activation. Specifically, the voltage supply for the CAN bus on the printed circuit board (PCB) A013 has failed or been interrupted, resulting in no functions available and no display.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Farmer 400 Vario series
• Favorit 700 Vario series
• Favorit 900 Vario series
• 300 Vario series
• 400 Vario series
• 700 Vario series
• 800 Vario series
• 900 Vario series
• 916
• 920
• 924
• 926
• 930

1. 1

   Locate the A013 Fuse Board, which is typically located behind the panel on the right side of the cab.

2. 2

   Inspect microfuses F040 and F041 on the A013 board, as these directly protect the CAN bus voltage supply for this circuit.

3. 3

   Test the A013 board to verify it is outputting the correct voltage to the CAN bus network.

4. 4

   Inspect the CAN bus wiring for breaks, shorts to ground, or shorts to positive. With the battery disconnected, test the total resistance of the CAN bus (it should measure 60 Ohms; if it measures 120 Ohms, there is a wiring break or a defective terminating resistor).

5. 5

   Check for corroded connectors, weak battery voltage, or poor grounding, which frequently destabilize CAN bus communication.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery before working on the electrical system.

2. 2

   Replace Fuses

   If fuses F040 or F041 are blown, replace them with new microfuses of the exact same amperage rating.

3. 3

   Repair Wiring

   If the fuses are intact but the CAN bus resistance or voltage tests fail, trace the wiring harness from the A013 board to the A002 enhanced control ECU. Repair any chafed wires, broken lines, or corroded pins.

4. 4

   Test/Replace the A013 Board

   If the wiring is good and the fuses are intact, but the CAN bus is still not receiving power, the A013 printed circuit board itself has likely failed internally. The board will need to be sent out for repair or replaced entirely.

5. 5

   Clear Codes

   Reconnect the battery, turn the key on, and use the tractor's terminal or a diagnostic tool (FENDIAS/SERDIA) to clear the fault codes.

6. 6

   Functional Test

   Test the 4WD and differential lock engagement switches to ensure full functionality has returned and no new codes populate.