Fendt 4.1.2C – Transmission Control module (Transmission ECU): Signal fault from Neutral / Active stationary mode button

Fault code 4.1.2C indicates a Signal fault originating from the button used to toggle between 'Neutral' and 'Active stationary mode' (also referred to as 'Active Standstill'). The system designates this button component as A003 or A034. When this signal fails, the tractor cannot reliably determine if the operator is requesting neutral or active standstill, prompting the system to restrict functionality.

• 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
• 815
• 817
• 818
• Fendt 300 Vario
• Fendt 400 Vario / Farmer 400
• Fendt 700 Vario / Favorit 700
• Fendt 800 Vario
• Fendt 900 Vario / Favorit 900

1. 1

   Verify the operating state, as the tractor will default to Auxiliary operation and requires an ignition cycle to reset.

2. 2

   Consult the specific Transmission control electrical circuit diagram for the A003/A034 circuit.

3. 3

   Inspect the physical neutral selection button on the main drive joystick (A003) or armrest control panel (A034) for sticking, debris, or lack of tactile feedback.

4. 4

   Disconnect the harness at the base of the joystick/armrest and use a multimeter to test the continuity of the neutral button switch when pressed.

5. 5

   Check the wiring harness between the joystick/armrest and the Transmission Control ECU for chafed wires, broken pins, or corrosion.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical shorts during repair.

2. 2

   Access the Component

   Remove the trim or mounting screws securing the main Vario joystick (A003) or the armrest control panel (A034) to access the wiring connections.

3. 3

   Isolate the Fault

   If the multimeter test showed an open circuit when the button is pressed (or a continuous short), the internal microswitch or the joystick's CAN circuit board has failed. If the button tests fine, repair the damaged section of the wiring harness leading to the Transmission ECU.

4. 4

   Replace or Repair the Joystick

   Replace the entire joystick assembly or send the unit to a specialized agricultural electronics repair service (such as Ilgenfritz Mechatronics) to have the internal CAN circuit board and microswitches rebuilt.

5. 5

   Reassembly

   Reconnect the electrical harness to the new or repaired joystick/panel. Secure the assembly back into the armrest.

6. 6

   Reset

   Reconnect the battery. Turn the ignition ON and OFF to clear the locked selection state. Start the tractor and test the toggle between Neutral and Active stationary mode to ensure the code is cleared.