Fendt 4.1.29 – Transmission Control / Enhanced Control ECU (A002): A034 - Driving switch, CAN bus; joystick centre position

Signal fault or Signal failure. The system is unable to read the correct center/rest position signal from the A034 driving switch (the main Vario joystick) over the CAN bus.

• 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
• 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)
• Farmer 400
• Fendt 700 Vario (COM III)
• Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)
• Favorit 900
• 916
• 920
• 924
• 926
• 930

1. 1

   Connect the FENDIAS diagnostic tool to read the A034 joystick data and verify if the signal fault is active or stored.

2. 2

   Check the CAN bus wiring harness and connectors between the A002 ECU and the A034 joystick (reference the 'Transmission control' or 'Joystick CAN' circuit diagrams).

3. 3

   Verify the 8.5V power supply to the joystick by checking the corresponding fuses (e.g., Fuse 7 or Fuse 13 on the A013 circuit board).

1. 1

   Inspect the Harness

   Repair any broken wires, corroded pins, or loose connectors found during the diagnostic checks between the ECU and the joystick.

2. 2

   Replace or Repair the Joystick

   If the wiring and voltage supply are intact, the signal failure is internal to the A034 joystick (often a failure of the internal CAN circuit board). The joystick must be replaced or sent to a specialized electronics repair facility.

3. 3

   EOL Programming

   If the A034 joystick is replaced, you must run a new EOL (End of Line) programming sequence using the FENDIAS diagnostic software. This calibrates the new joystick and clears the checksum/initialization errors so the tractor's ECU recognizes the new component.