Fendt 04.1.2C – Transmission Control System (Travel Range / Operating Range): A036 / A039 / A100 - MFA, multifunction armrest: Neutral/Active Stationary button (or Neutral/Active Standstill button) - Faulty button, Signal fault.

The system is receiving an implausible signal from the Neutral button located on the multifunction armrest. This is typically caused by a mechanically stuck button, a failed internal microswitch, or a wiring/communication fault between the armrest control panel and the tractor's main control unit.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 200 V/F/P Vario series
• Fendt 300 Vario series (including COM III)
• Fendt 400 Vario series
• Fendt 700 Vario series (including SCR models)
• Fendt 800 Vario series
• Fendt 900 Vario series (916, 920, 922, 924, 927, 930, 933, 936)

1. 1

   Check the Neutral/Active Stationary button on the joystick/armrest for physical damage, sticking, or accumulated dirt/debris.

2. 2

   Use the onboard diagnostic menu or FENDIAS software to monitor the live state of the Neutral button and verify state changes.

3. 3

   Inspect the wiring harness and connectors between the armrest control panel (A036/A039/A100) and the main transmission ECU for continuity, chafing, or corrosion.

4. 4

   Clear the fault memory (press buttons A, B, and C simultaneously on the instrument cluster) and cycle the key to check if the fault returns.

1. 1

   Disconnect Power

   Turn off the ignition and disconnect the battery to prevent electrical shorts while working on the armrest.

2. 2

   Access the Armrest Internals

   Carefully remove the plastic trim covers on the multifunction armrest to expose the joystick and the button control boards.

3. 3

   Clean the Contacts

   If the button is physically sticking, use an electrical contact cleaner to clear out dust, agricultural debris, or spilled liquids from the button housing.

4. 4

   Replace the Component

   If the microswitch is internally shorted or open (and cleaning does not resolve the issue), the specific button board or the entire joystick assembly must be replaced.

5. 5

   Reassembly & Calibration

   Reinstall the armrest components and reconnect the battery.

6. 6

   Post-Repair Testing

   Turn the ignition on, clear the stored fault codes, and test the Neutral/Active Stationary function. If the joystick was completely replaced, a transmission/joystick calibration via the tractor's terminal or FENDIAS software may be required.