Fendt 4.1.01 – TRANSMISSION: Acceleration ramp I-IV — Signal fault

The control unit is not receiving a valid signal from the acceleration ramp sliding switch (potentiometer) located on the main driving joystick (component A034). This indicates an issue with the 8.5V sensor supply voltage or a break/short in the signal circuit, causing the tractor to restrict functions to auxiliary operation or emergency mode.

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

1. 1

   Check Fuse 5 on the A013 circuit board (microfuses PCB), which protects the 8.5V supply circuit for the joystick

2. 2

   Verify that the 8.5V supply voltage is reaching the joystick connector using a multimeter

3. 3

   Inspect the wiring harness and connectors between the joystick (A034) and the transmission control module for breaks, corrosion, or pinched wires

4. 4

   Monitor the signal from the acceleration ramp sliding switch using FENDIAS diagnostic software or a multimeter to ensure it changes smoothly through positions I to IV

1. 1

   Power Down

   Turn off the tractor and locate the A013 microfuse circuit board (usually located in the side console or dashboard area, depending on the model).

2. 2

   Fuse Replacement

   If Fuse 5 is blown, replace it with a fuse of the exact same amperage. Turn the tractor on and test the acceleration ramp switch. If the fuse blows again immediately, there is a short circuit in the joystick or the wiring harness.

3. 3

   Harness Repair

   If the fuse is intact but the 8.5V supply is missing at the joystick, trace the wiring back to the transmission ECU and repair any broken wires or corroded connector pins.

4. 4

   Joystick Repair/Replacement

   If the 8.5V supply is present but the signal is missing or erratic, the internal potentiometer in the joystick (A034) has failed. You must either send the joystick to a specialized agricultural electronics repair service to have the internal foil buttons/potentiometers rebuilt, or replace the entire joystick assembly.

5. 5

   Calibration

   After repairing or replacing the joystick, clear the fault codes. You must then perform a calibration of the potentiometer 'Accelerator resolution' (Sliding switch on A034 - joystick) using calibration code 4010 via the tractor's terminal.