Fendt 07.1.01 – MFA (Multifunction Armrest) module: A039 - MFA, multifunction armrest: Button, front PTO ON/OFF - Signal fault

The system detects an electrical signal fault from the Front PTO ON/OFF button, typically caused by a physically faulty button on the armrest or a CAN bus communication error preventing the button's signal from reaching the tractor's control modules.

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

1. 1

   Attempt to engage the front PTO by pressing and holding the button for at least 5 seconds (Emergency Mode Test) to verify if the mechanical PTO clutch and solenoids are functioning, isolating the issue to the button's momentary signal

2. 2

   Check the tractor's terminal for active CAN bus faults (e.g., A004/A002) to determine if the issue is an MFA bus connection failure rather than an isolated button fault

3. 3

   Inspect the Front PTO button for sticking, lack of tactile feedback, or signs of liquid ingress (e.g., spilled drinks)

4. 4

   Inspect the wiring harness connecting the A039 MFA to the central electrical system for pinched wires or loose connector pins

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent short circuits while working on the armrest electronics.

2. 2

   Access the MFA

   Carefully remove the retaining screws on the underside of the multifunction armrest to separate the top plastic housing.

3. 3

   Inspect the Switch Matrix

   Locate the Front PTO ON/OFF switch on the circuit board. Clean the contact area with electronic contact cleaner if debris or sticky residue is present.

4. 4

   Replace the Component

   If the microswitch/membrane is damaged and your dealership supplies sub-components, desolder/replace the individual switch. If the button is integrated into a sealed printed circuit board (PCB) matrix, the entire MFA top board or armrest assembly must be replaced.

5. 5

   Reassembly

   Reconnect the MFA wiring harness and reassemble the armrest housing.

6. 6

   Clear Codes & Calibrate

   Reconnect the battery. Use the FENDIAS diagnostic software to clear the 07.1.01 fault code. If a completely new MFA module was installed, an EOL (End of Line) programming procedure must be performed via FENDIAS to configure the armrest to the tractor's specific options.

7. 7

   Operational Test

   Start the tractor and test the front PTO engagement under normal operation.