Fendt 03.1.40 – A039 / A100 (MFA, multifunction armrest): Invalid parameters for hand throttle and throttle pedal speed range.

The system has detected that the calibration values for the accelerator pedal resolution or hand throttle are out of range, missing, or corrupted (such as an EEPROM checksum error). As a safety consequence, the tractor's computer ignores the erratic sensor inputs and uses predefined default values. This typically results in the throttle pedal mode becoming inoperable or restricted, and the TMS (Tractor Management System) may be switched off.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 300 Vario (COM III, S4)
• 400 Vario (COM III)
• 500 Vario (S4)
• 700 Vario (COM III, SCR)
• 800 Vario (COM III, S4)
• 900 Vario (COM III, S4)
• 922
• 924
• 927
• 930
• 933
• 936
• 409
• 410
• 411
• 412
• 1000 Vario S4
• 1038
• 1042
• 1046
• 1050
• 200 Vario

1. 1

   Verify the A034 driving switch/joystick accelerator pedal release potentiometer (slide switch) for physical damage, debris, or sticking.

2. 2

   Check for active vs. stored codes to determine if the module simply lost its calibration memory (e.g., due to a recent battery replacement or armrest disconnection).

3. 3

   Attempt a software calibration before replacing any hardware, as the code specifically points to invalid parameters.

1. 1

   Access diagnostic menu

   Turn the ignition on and access the tractor's diagnostic/calibration menu via the terminal.

2. 2

   Check preliminary conditions

   Ensure preliminary conditions are met (e.g., engine speed, transmission in neutral, emergency control not engaged).

3. 3

   Enter calibration code

   Enter Calibration Code 4010 (Accelerator pedal resolution / driving pedal resolution).

4. 4

   Cycle controls

   Follow the on-screen prompts to cycle the hand throttle and foot pedal through their full ranges of motion.

5. 5

   Save calibration data

   If the calibration proceeds without errors, the message 'OK' is displayed, and the new sensor settings are stored in the EEPROM. Turn the ignition key to position 0 to save the data.

6. 6

   Troubleshoot calibration failures

   If the terminal displays 'ERROR' or throws a secondary calibration fault code (e.g., F01: Conditions not met, F02: Calibrated value invalid, F03: MFA not responding, F08: Calibration taking too long), the physical potentiometer, wiring harness, or the MFA module itself is defective.

7. 7

   Replace hardware

   If calibration fails repeatedly, replace the faulty MFA multifunction armrest or the specific slide switch component.

8. 8

   Perform post-repair programming

   If the MFA armrest (A039/A100) is replaced, you must perform EOL (End of Line) programming using FENDIAS dealer software, followed by a complete block of calibrations (including 4010).