Fendt 04.1.26 – A100 (MFA, Multifunction Armrest) or A036 (Control Console / Dashboard): A036 - Pedal mode key / A100 - MFA, multifunction armrest.

A signal fault where the accelerator pedal mode button/key is faulty. The throttle pedal mode becomes inoperable, and the Tractor Management System (TMS) may be restricted or switched off.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario
• Fendt 700 Vario (COM III / SCR)
• Fendt 800 Vario
• Fendt 900 Vario (COM III / SCR / S4)

1. 1

   Inspect the pedal mode button on the multifunction armrest/joystick for physical damage, sticking, or debris preventing the button from returning to its neutral position.

2. 2

   Check the wiring harness and plug connections (e.g., AMP Superseal connectors) leading from the multifunction armrest to the main cab harness for corrosion, bent pins, or wire chafing.

3. 3

   Connect the AGCO 2x4 CANUSB diagnostic scanner and use the FENDIAS software to monitor the live state of the pedal mode key to verify if the ECU registers the button press.

4. 4

   Verify the 12V / 8.5V supply voltages to the armrest console by checking associated fuses in the cab fuse panel.

1. 1

   Power Down

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

2. 2

   Access the Switch

   Carefully remove the housing/cover of the multifunction armrest or joystick to access the internal circuit board and switches.

3. 3

   Test the Switch

   Use a multimeter to test the pedal mode microswitch for continuity when pressed.

4. 4

   Component Replacement

   If the switch fails the continuity test and is a replaceable toggle/push button, desolder/disconnect the faulty switch and install the replacement. Note: If the button is integrated into the main circuit board, the entire joystick/drive lever may need to be sent to a specialized agricultural electronics repair center for board-level repair.

5. 5

   Reassembly

   Reassemble the armrest housing, ensuring no wires are pinched.

6. 6

   Clear Codes

   Reconnect the battery, turn on the ignition, and use the FENDIAS tool (or the tractor's onboard terminal) to clear the 04.1.26 fault code. Test the pedal mode function to ensure the repair was successful.