Fendt 9.1.B3 – A004 - ECU, control panel: A004 - Depth control setpoint potentiometer — Switch / A004 signal fault

Depth control setpoint potentiometer is sending no values or incorrect values. As a result, the depth setpoint for the front power lift cannot be set.

• 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 Favorit 900 Vario series (916, 920, 924, 926, 930)
• Fendt Favorit 700 Vario series (711, 712, 714, 716)
• Fendt Farmer 400 Vario series (409, 410, 411, 412)
• Fendt 800 Vario series (815, 817, 818)

1. 1

   Check CAN Bus Communication: Verify that the A004 control console is communicating properly. If there are other A004 bus faults (like 9.1.C0 "Control console not available or bus not connected"), address the CAN bus or power supply to the console first.

2. 2

   Inspect the Potentiometer: Physically inspect the depth control rotary dial/potentiometer on the control console for mechanical damage, sticking, or excessive wear.

3. 3

   Wiring and Connector Check: Inspect the wiring harness and connectors between the depth control setpoint potentiometer and the A004 control console for continuity, corrosion, shorts to ground, or open circuits.

4. 4

   Signal Test: Test the signal output of the potentiometer using a multimeter or FENDIAS diagnostic tool to see if the voltage sweeps smoothly as the dial is turned.

1. 1

   Disconnect Power

   Turn off the tractor and disconnect the battery to prevent electrical shorts during console disassembly.

2. 2

   Access the Control Console

   Carefully remove the trim and mounting hardware to access the internal components of the A004 control console.

3. 3

   Replace the Potentiometer

   If the wiring is intact but the signal is faulty, remove the defective depth control setpoint potentiometer and install the replacement part. (Note: If the potentiometer is hard-soldered or integrated directly into the A004 board and cannot be serviced separately, the entire A004 control console may require replacement or specialized board-level repair).

4. 4

   Reassemble and Reconnect

   Reinstall the control console and reconnect the battery.

5. 5

   Calibrate the Potentiometer

   A new potentiometer must be calibrated to the system. Use the tractor's onboard diagnostic terminal or FENDIAS to run the calibration procedure. The specific calibration code for the front power lift depth control setpoint potentiometer is "9001" (Note: Code 9.1.B2 will trigger if it is not calibrated).

6. 6

   Clear Codes and Test

   Clear the stored 9.1.B3 fault code and test the front power lift to ensure the depth setpoint can now be adjusted properly.