Fendt 06.1.16 – MFA (Multifunction Armrest): A039 (or A100) - MFA, multifunction armrest. Speed preselection button 540.

The system has detected a signal fault from the 540 RPM rear PTO speed preselection button located on the multifunction armrest. This usually means the button is faulty, stuck, or has an internal open/short circuit. As a safety and operational precaution, the PTO speed cannot be modified or selected while this code is active.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, SCR)
• Fendt 800 Vario (COM III, SCR)
• Fendt 900 Vario (COM III, SCR, Gen6)

1. 1

   Inspect the 540 PTO speed preselection button on the multifunction armrest for physical damage, sticking, or accumulated dirt/debris that might be holding the button down.

2. 2

   Attempt to clear the fault code via the tractor's terminal to determine if the fault is active or just a stored intermittent error.

3. 3

   Use the Fendt diagnostic tool (FENDIAS) to monitor the live signal from the MFA. Press the 540 button and observe if the state changes in the software.

4. 4

   Verify the wiring harness and CAN bus connections between the MFA and the Basic Control Unit (EXT) to rule out a communication error masquerading as a button fault.

1. 1

   Disconnect battery

   Turn off the tractor and disconnect the battery before disassembling the armrest to prevent electrical shorts.

2. 2

   Remove trim panels

   Carefully remove the trim panels on the multifunction armrest to access the internal keypad/switch modules.

3. 3

   Clean buttons

   Clean the area around the PTO speed preselection buttons with electrical contact cleaner. If the button was merely stuck due to debris, reassemble and test.

4. 4

   Replace switch or module

   If the button is internally faulty, replace the affected switch or the entire MFA keypad module (depending on whether your specific Vario generation allows individual button replacement or requires a modular swap).

5. 5

   Reassemble and reconnect

   Reassemble the armrest and reconnect the battery.

6. 6

   Clear fault code

   Turn on the ignition, navigate to the fault code menu on the Vario terminal, and clear the stored 06.1.16 code.

7. 7

   Test PTO

   Test the rear PTO engagement and speed selection to ensure the 540 RPM setting engages properly without throwing a new code.