Fendt 4.1.03 – Transmission Control Unit (A002 ECU): Neumaier reverse drive facility clutch pedal potentiometer — Signal fault

The control unit is receiving an erratic, out-of-range, or missing electrical signal from the potentiometer that monitors the position of the clutch pedal when the tractor is operating in the Neumaier reverse drive mode (RÜFA). This is frequently caused by a failure in the 8.5 V power supply to the sensor.

• 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
• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 300 Vario series (COM III)
• Fendt 400 Vario series (411, 412, 413, 414, 415 COM III)
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series

1. 1

   Check fuse 9 on the A013 circuit board for a blown fuse causing a loss of the 8.5 V supply.

2. 2

   Use a multimeter at the clutch pedal potentiometer connector to verify that the 8.5 V reference voltage is present.

3. 3

   Check the wiring between the Neumaier clutch pedal potentiometer and the A002 Transmission ECU for chafing, breaks, or loose connector pins.

4. 4

   Attempt to recalibrate the clutch pedal using the tractor's onboard terminal to see if the sensor simply drifted out of tolerance.

1. 1

   Power Down

   Turn off the tractor and remove the key.

2. 2

   Fuse Replacement

   If fuse 9 on the A013 board was found to be blown during diagnostics, replace it. If it blows again immediately upon key-on, trace the wiring for a short to ground.

3. 3

   Remove the Potentiometer

   If the wiring and voltage are good but the signal is still faulty, locate the clutch pedal potentiometer on the Neumaier reverse drive pedal assembly. Disconnect the electrical harness and unbolt the sensor from the pedal linkage.

4. 4

   Install the New Sensor

   Mount the replacement potentiometer, ensuring the mechanical linkage is properly aligned so the sensor sweeps through its correct range of motion without binding. Reconnect the electrical harness.

5. 5

   Perform EOL Calibration

   You must calibrate the new sensor for the transmission ECU to recognize its sweep. Enter the Fendt diagnostic menu and run the clutch calibration procedure using Calibration Code "4011".

6. 6

   Clear Codes

   Clear the stored 4.1.03 fault code from the memory and test the reverse drive facility to ensure normal operation.