Fendt 4.1.23 – Transmission Control Unit / A002 ECU: A034 - Driving switch, CAN bus (Joystick "Cruise Control Activate" / "Tempomat cruise control ON")

This code indicates a signal fault or signal failure originating from the cruise control activation button on the main driving joystick. The system is detecting an error in the CAN bus communication specifically tied to this input on the A034 driving switch, which restricts operations to Auxiliary Operation only and disables cruise control/TMS functions.

• 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
• 411
• 412
• 415
• 711
• 712
• 714
• 716
• 718
• 815
• 817
• 818
• 820
• 916
• 920
• 924
• 926
• 930

1. 1

   Test other joystick functions to determine if only the cruise control button is unresponsive or if the entire joystick is failing

2. 2

   Verify the 8.5V/12V power supply to the CAN bus circuit board and check the A013 fuse board (fuses F047, F040, or F041 depending on model)

3. 3

   Inspect the wiring harness and physical CAN bus connection between the A034 joystick and the A002 Enhanced Control ECU for continuity, corrosion, or pin damage

4. 4

   Check for concurrent CAN bus error codes (e.g., 0.0.1F or 1.1.9F) which indicate a complete loss of data transfer from the drive switch

1. 1

   Power Down

   Turn off the tractor ignition and disconnect the battery to prevent electrical spikes.

2. 2

   Access the Joystick

   Carefully remove the trim on the multifunction armrest to expose the base and wiring of the A034 driving switch/joystick.

3. 3

   Inspect the Switch

   If the wiring tests fine, the fault is almost certainly internal to the joystick (a failed microswitch for the cruise control button or a cracked internal CAN circuit board).

4. 4

   Repair or Replace

   Send the joystick to a specialized agricultural electronics repair center to rebuild the internal circuit board and replace the microswitches, or replace the entire A034 joystick assembly with a new OEM unit.

5. 5

   Reassembly & Calibration

   Install the repaired/new joystick. Reconnect the battery and turn on the ignition. Calibrate the new joystick using the tractor's terminal (Calibration code 4010 is used for the accelerator resolution/sliding switch on the A034 joystick).

6. 6

   Clear Codes

   Clear the fault codes from the system and test drive to ensure cruise control engages properly.