Fendt 5.1.93 – Tractor Management System (TMS) / EPC REAR ACTUATORS: A003, A034 - 'Front automatic ON / OFF' key in joystick — Signal fault

The system has detected an implausible signal, an open circuit, or a short circuit originating from the 'Front automatic ON / OFF' button located on the Vario joystick. The front automatic mode will not function, and the system disables the feature to prevent erratic operation.

• 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 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

1. 1

   Verify the symptom by confirming that the front automatic mode fails to engage when the button is pressed

2. 2

   Inspect the joystick (A003) for physical wear, damage, or tearing on the membrane keypad and foil buttons

3. 3

   Check the wiring harness and the main connector at the base of the joystick for continuity, corrosion, or loose pins

4. 4

   Connect the FENDIAS diagnostic software and monitor the live state of the 'Front automatic ON / OFF' button to determine if the internal microswitch or membrane is defective

5. 5

   Check for related CAN bus communication fault codes (e.g., involving ECU A034) to rule out a broader internal CAN board or main harness failure

1. 1

   Preparation

   Power down the tractor and disconnect the battery to ensure electrical safety.

2. 2

   Disassembly

   Carefully disassemble the right-hand armrest/side control console to access the base of the joystick.

3. 3

   Removal

   Disconnect the main electrical connector for the Vario joystick and unbolt the joystick assembly from the armrest mount.

4. 4

   Repair or Replace

   Send the joystick to a specialized agricultural electronics repair center to have the internal membrane keypad and foil buttons rebuilt, or install a brand-new or remanufactured OEM Vario joystick assembly.

5. 5

   Installation

   Mount the new/repaired joystick into the armrest and securely reconnect the wiring harness. Reassemble the armrest console.

6. 6

   Reprogramming

   Reconnect the battery. Connect the FENDIAS diagnostic tool. If a brand-new joystick was installed, an EOL (End of Line) reprogramming or teach-in procedure may be required for the ECU (A034) to recognize the new component.

7. 7

   Clear and Test

   Clear the 5.1.93 fault code and test the front automatic ON/OFF function to confirm the repair.