Fendt A.1.B3 – Enhanced Control ECU (A002) or Multifunction Armrest MFA (A039 / A100): Crossgate lever (A003 / A034 - Driving switch, CAN bus) interference or missing

Interference with X- and Y-axis signals; crossgate lever missing, or recognition of centre position is faulty. As a result, the auxiliary control valves cannot be operated, or the valve positions cannot be controlled accurately.

• 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 Farmer 400 series
• Fendt Favorit 700 and 900 series
• Fendt 300, 400, 700, 800, and 900 Vario series (including COM III and S4 generations)

1. 1

   Check if the crossgate lever (joystick) is physically damaged, loose, or disconnected.

2. 2

   Inspect the wiring harness and connectors between the crossgate lever (A034/A003) and the control module for breaks, short circuits, or corroded pins.

3. 3

   Determine if the lever has simply lost its calibration memory (the zero-position signals of the X and Y axes must be identical to the programmed rest position).

1. 1

   Power Down

   Turn off the tractor ignition to safely inspect the electrical connections on the multifunction armrest.

2. 2

   Inspect and Reconnect

   Remove the armrest cover to access the bottom of the crossgate lever. Disconnect the main harness connector, clean the contacts with electrical contact cleaner, and securely reconnect it.

3. 3

   Check for Harness Damage

   Use a multimeter to verify continuity on the CAN bus lines between the joystick connector and the ECU. Repair any broken wires.

4. 4

   Recalibrate the Lever

   Turn the ignition back on. Access the tractor's diagnostic/calibration menu (FENDIAS or onboard terminal) and run Calibration Code 1001 (Crossgate lever calibration). Follow the on-screen prompts to teach the system the center, maximum X, and maximum Y axis positions.

5. 5

   Replace if Defective

   If the calibration fails, or if the internal potentiometers/foil buttons are physically worn out and dropping signals, the crossgate lever assembly must be replaced. After installing the new lever, you must run Calibration Code 1001 again to initialize it.