Fendt 4.1.27 – A002 ECU (Enhanced control): Rapid reverse button (F/R rocker) fault

The F/R (Forward/Reverse) rocker switch located in the armrest joystick is not functioning (often referred to as a joystick lock). As a result, the rapid reverse function will not work.

• 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
• Fendt 300 Vario (COM III)
• Fendt Farmer 400 / 400 Vario (COM III)
• Fendt Favorit 700 / 700 Vario (COM III)
• Fendt Favorit 900 / 900 Vario (COM III)
• Fendt 800 Vario (COM III)

1. 1

   Connect the tractor to the FENDIAS diagnostic program and run a check specifically on the A034 - Drive switch

2. 2

   Check the CAN connection (enhanced control BUS) between the A002 ECU (enhanced control) and the A034 Drive switch for wiring faults, continuity issues, or damaged pins

3. 3

   Attempt to clear the fault codes from the memory (on some older terminals, simultaneously pressing keys D, B, and C deletes fault codes) to see if the fault is a hard failure or an intermittent glitch

1. 1

   Inspect the Joystick

   Check the physical F/R rocker switch on the A034 joystick for mechanical damage, sticking, or debris.

2. 2

   Wiring Repair

   If the FENDIAS diagnostic tool or multimeter reveals a break in the CAN communication between the A002 ECU and the A034 joystick, repair the wiring harness as per the "Enhanced control Bus" circuit diagram.

3. 3

   Replace the Joystick

   If the internal switch or circuit board of the joystick has failed and cannot be repaired, the A034 joystick unit must be replaced.

4. 4

   EOL Programming

   If the A034 joystick is replaced, or if the system suffers an initialization/EEPROM error, you must run a new EOL (End of Line) programming for the A034 joystick so the A002 ECU recognizes the new component.