Fendt 4.1.20 – A002 / A034 / A100: Accelerator pedal release potentiometer not calibrated or EEPROM checksum error

The accelerator pedal release potentiometer (slide switch) is not calibrated, or there is an EEPROM checksum error, causing the TMS to disable the throttle pedal mode.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Fendt 400 Vario COM III
• Fendt 700 Vario COM III
• Fendt 800 Vario COM III
• Fendt 900 Vario COM III
• Fendt Vario S4 Series (e.g., 927, 930, 933, 936, 939)

1. 1

   Verify symptoms by confirming that the tractor cannot be driven in accelerator pedal mode.

2. 2

   Check for related fault code 4.1.22 (Accelerator pedal release potentiometer faulty / signal fault). If present, the potentiometer is likely physically defective rather than just uncalibrated.

3. 3

   Inspect the physical condition of the joystick and the slide switch for obvious damage, debris, or sticking.

1. 1

   Initiate Calibration

   Access the tractor's diagnostic/calibration menu via the Variotronic terminal.

2. 2

   Enter Calibration Code

   Input calibration code 4010 (Driving pedal resolution / Accelerator pedal release potentiometer calibration).

3. 3

   Run the Procedure

   Follow the on-screen prompts to calibrate the current actuator position.

4. 4

   Monitor for Calibration Errors

   During the process, watch for specific calibration failure codes: F02 (invalid value), F03 (A100 MFA not responding), or F08 (taking more than 30 seconds).

5. 5

   Clear and Test

   If the calibration completes successfully, clear the fault codes and test the accelerator pedal mode.

6. 6

   Replace Components

   If the calibration fails (e.g., throws an F02 error) or if the 4.1.20 code immediately returns, replace the potentiometer or send the joystick out for professional repair/replacement.

7. 7

   Recalibrate

   After replacing any parts, rerun calibration code 4010 to marry the new sensor values to the ECU.