Fendt 06.1.15 – A039 - MFA (Multifunction Armrest): A039 - MFA, multifunction armrest: Speed selector button NEUTRAL

The control system is not receiving a valid signal from the Neutral PTO speed selector button located on the multifunction armrest, preventing the rear PTO speed from being modified or selected and causing the PTO to disengage or fail to function.

• 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 Vario (V/F/P)
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III and SCR)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III and SCR)

1. 1

   Attempt to clear the fault code from the instrument cluster to determine if it is a hard fault or an intermittent glitch.

2. 2

   Physically inspect the Neutral PTO speed selector button on the armrest to see if it feels sticky, collapsed, or mechanically broken.

3. 3

   Consult the PTO circuit diagram (Sheet 32 or Sheet 10 in Fendt workshop manuals).

4. 4

   Check the wiring harness and connectors between the A039 Multifunction Armrest (connector X1401) and the central electrical system for continuity issues, chafed wires, or loose pins.

5. 5

   Use a 160-pin adapter box or FENDIAS diagnostic software to monitor live inputs from the A039 module to verify if the button press is registering at the ECU level.

1. 1

   Disconnect Power

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

2. 2

   Access the Armrest Internals

   Carefully remove the trim panels and retaining screws on the A039 multifunction armrest to access the internal switch panels and circuit boards.

3. 3

   Inspect the Button/Keypad

   Locate the PTO speed selector switch group. Disconnect the wiring plug specific to this switch block.

4. 4

   Test the Switch

   Use a multimeter to test the continuity of the Neutral button when pressed.

5. 5

   Repair Wiring or Replace Component

   If the button tests good but the signal isn't reaching the ECU, repair the damaged wiring harness or clean the corroded connector pins. If the button itself has failed internally (no continuity or shorted), replace the button, the specific keypad sub-assembly, or the entire armrest control module.

6. 6

   Reassembly and Calibration

   Reconnect all plugs, reassemble the armrest, and reconnect the battery.

7. 7

   Clear Faults and Test

   Turn the ignition on, clear the stored 06.1.15 fault code from the tractor's memory, and test the PTO Neutral selection to ensure the PTO engages and disengages properly without throwing the code.