Fendt 09.1.45 – A039 - MFA (Multifunction Armrest): A039 - MFA, multifunction armrest: Transport button, SAH front power lift

A signal fault caused by a faulty button (e.g., the button is internally shorted, stuck, or has an open circuit). As a safety consequence, the tractor's system renders the button inoperable until the next trouble-free cold start.

• 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)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III) (Models 922, 924, 927, 930, 933, 936)

1. 1

   Physical Inspection: Inspect the front power lift transport button on the multifunction armrest. Check if the button is physically stuck, depressed, or jammed due to dirt, spilled liquids, or debris.

2. 2

   Cold Start Reset: Because the system locks the button out upon detecting the fault, turn the tractor off completely, let it sit to power down the ECUs, and perform a "cold start." If the button was only temporarily stuck, the fault may clear and functionality will return.

3. 3

   Adapter Box Testing: If the fault persists, Fendt workshop manuals recommend testing the A039 MFA unit using the Fendt 160-pin adapter box to verify if the signal fault is internal to the armrest's circuit board or a wiring issue.

4. 4

   Clear Codes: Use the tractor's terminal or FENDIAS diagnostic software to clear the stored fault code. If the code immediately returns upon pressing the button, the switch has failed.

1. 1

   Disconnect Power

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

2. 2

   Clean the Keypad

   Use an electronics-safe contact cleaner around the edges of the transport button to dissolve any sticky residue. Work the button gently to see if it frees up.

3. 3

   Disassemble the Armrest

   If cleaning does not work, remove the retaining screws on the underside of the A039 multifunction armrest to lift the top cover and access the internal keypad and joystick wiring.

4. 4

   Inspect Connections

   Check the ribbon cables and wiring harnesses connecting the front power lift keypad to the MFA's main internal control board. Re-seat any loose connectors.

5. 5

   Replace the Component

   If the button switch itself has failed internally (permanent signal fault), you will need to replace the affected keypad sub-assembly or the entire multifunction armrest (depending on the specific trim level, as Fendt often services the MFA buttons as a complete module).

6. 6

   Reassemble and Test

   Reassemble the armrest housing, reconnect the battery, and perform a cold start. Test the front power lift transport button to confirm the 09.1.45 code does not return.