Fendt 08.1.45 – MFA (Multifunction Armrest) control module (A039 / A100): A039 - MFA, multifunction armrest. Transport button, SAH rear power lift

Faulty button, signal fault. The system registers a signal error from the transport/quick lift button on the multifunction armrest. As a safety precaution, the button is rendered inoperable until the next trouble-free cold start (ignition OFF/ON).

• 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)
• Fendt 900 Vario (COM III & SCR)
• Fendt 922
• Fendt 924
• Fendt 927
• Fendt 930
• Fendt 933
• Fendt 936

1. 1

   Perform a cold start reset by turning the tractor's ignition completely OFF, waiting a few moments, and turning it back ON to see if the fault clears.

2. 2

   Inspect the transport/quick lift button on the multifunction armrest for physical damage, sticking, or accumulated dirt/debris.

3. 3

   Check the internal wiring ribbon cables and harness connections underneath the multifunction armrest cover leading to the A039/A100 module.

4. 4

   Verify if the rear power lift can still be operated using the external fender switches to isolate the issue to the MFA button/circuit.

1. 1

   Disconnect Power

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

2. 2

   Disassemble the MFA

   Carefully remove the retaining screws on the multifunction armrest housing to access the internal circuit boards and button pads.

3. 3

   Clean the Contacts

   If the button is sticking, use a specialized electronic contact cleaner to clean the microswitch and the surrounding area.

4. 4

   Replace the Switch/Module

   If the microswitch is permanently damaged or shorted, it must be replaced. Note: Depending on the specific armrest revision, individual buttons may not be serviceable, requiring the replacement of the specific keypad insert or the entire MFA joystick/armrest circuit board.

5. 5

   Reassemble and Calibrate

   Reconnect the wiring harnesses, reassemble the armrest, reconnect the battery, and perform a cold start to verify the fault code 08.1.45 has cleared.