Fendt 04.1.71 – A039 (or A100) MFA (Multifunction Armrest): A039 - MFA, multifunction armrest Cruise control button, C2

Signal fault caused by a faulty C2 cruise control button on the Vario joystick, which prevents Tempomat cruise control 2 from being activated.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 200 V/F/P Vario series
• 300 Vario series
• 400 Vario series (e.g., COM III)
• 700 Vario series (e.g., COM III, SCR)
• 800 Vario series
• 900 Vario series (e.g., COM III, SCR)

1. 1

   Visually inspect the C2 cruise control button on the Vario drive lever (joystick) for physical damage, sticking, or accumulated dirt/debris that might be holding the contact down.

2. 2

   Use FENDIAS (Fendt diagnostic software) and navigate to the Variowin joystick diagnostics to monitor the live state of the C2 button. Check if the signal is permanently open or shorted.

3. 3

   Check the wiring harness and connectors between the joystick handle and the MFA control board for continuity, pinched wires, or pin damage.

4. 4

   Verify if other joystick buttons (such as Cruise Control C1 - fault code 04.1.70) are functioning correctly to rule out a complete joystick communication failure or a broader MFA bus fault.

1. 1

   Power down the tractor and disconnect the battery

   to prevent electrical shorts during disassembly.

2. 2

   Carefully remove the Vario drive lever / joystick assembly

   from the multifunction armrest.

3. 3

   Disassemble the joystick handle

   to access the internal switch plate and button contacts.

4. 4

   Test the specific C2 microswitch with a multimeter.

   If the button or the board is faulty, you have three options: replace the individual button/switch plate, replace the entire joystick, or send the joystick to a specialized agricultural electronics repair center (such as Ilgenfritz Mechatronics) which can replace the internal microswitches.

5. 5

   Reassemble the joystick handle and reinstall it into the armrest

   ensuring all wiring connectors are securely seated.

6. 6

   Reconnect the battery and turn on the ignition.

7. 7

   Access the tractor's terminal to clear the fault codes from the memory

   (often done by pressing the specific arrow keys simultaneously on older displays, or via the terminal menu on newer models).

8. 8

   Perform a functional test

   to ensure Cruise Control 2 activates properly and the tractor holds the set speed.