Fendt 09.1.B2 – A039 - MFA (Multifunction Armrest): A039 - MFA, multifunction armrest: Setpoint potentiometer, front power lift - Setpoint value potentiometer not calibrated.

The system has lost the calibration values for the depth control setpoint dial/potentiometer used to operate the front power lift. The setpoint values cannot be set by the operator, and the front power lift will default to allowing only basic position control.

• 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 / S4)
• Fendt 800 Vario (COM III / S4)
• Fendt 900 Vario (COM III / S4)
• Fendt 916
• Fendt 920
• Fendt 922
• Fendt 924
• Fendt 926
• Fendt 927
• Fendt 930
• Fendt 933
• Fendt 936

1. 1

   Check for accompanying fault code 09.1.B3, which indicates a hardware signal fault (potentiometer sending no values or incorrect values) rather than just a calibration loss.

2. 2

   Inspect the front power lift depth control setpoint potentiometer on the multifunction armrest for physical damage, sticking, or liquid intrusion.

3. 3

   Ensure the A039 MFA is communicating properly with the tractor's basic control unit (ECU A050) and that no general MFA bus faults are active.

1. 1

   Prepare tractor for calibration

   Ensure the tractor is stationary, the engine is running at the specified RPM (usually around 1100 rpm), and the handbrake is applied.

2. 2

   Access diagnostics menu

   Access the Vario terminal diagnostics/calibration menu.

3. 3

   Enter calibration code

   Enter Calibration Code "9001" (Front EPC calibration / Front power lift calibration).

4. 4

   Sweep potentiometer

   Follow the on-screen prompts to sweep the setpoint potentiometer through its full range of motion so the A039 module can relearn the minimum and maximum voltage values.

5. 5

   Save calibration

   Save the calibration.

6. 6

   Clear fault codes

   Clear the stored fault codes from the tractor's memory (typically done by pressing and holding the designated clear/ESC keys on the terminal).

7. 7

   Replace parts if calibration fails

   If the calibration fails to complete, or if the potentiometer has an internal short/open circuit (triggering code 09.1.B3), the potentiometer or the entire multifunction armrest must be replaced, followed by repeating Calibration Code 9001.