Fendt 08.1.B2 – Rear EPC: Rotary switch, setpoint setting - Setpoint potentiometer not calibrated

The tractor's computer does not have a valid calibration value for the rear power lift's setpoint potentiometer. As a consequence, setpoint values can no longer be set by the operator, and the rear power lift will default to allowing only basic position control or external button operation.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III, SCR)
• Fendt 800 Vario (COM III, S4)
• Fendt 900 Vario (COM III, SCR, S4)

1. 1

   Verify fallback operation: Confirm that the rear power lift can still be operated via the external fender buttons or in basic position control mode to isolate the issue to the cabin input.

2. 2

   Physical inspection: Inspect the rotary switch/potentiometer on the multifunction armrest or side console for physical damage, liquid intrusion, or binding.

3. 3

   Wiring/Communication check: Ensure the MFA or control panel is communicating properly with the tractor's bus system. If other armrest buttons are also failing, it may be a broader MFA communication fault.

1. 1

   Prepare tractor for calibration

   Ensure the tractor is stationary, the engine is running (or ignition ON as specified by your exact model's dash prompts), and no other blocking faults are active.

2. 2

   Access diagnostics menu

   Access the tractor's Variotronic terminal / diagnostics menu.

3. 3

   Enter calibration code

   Enter the specific calibration code for the Rear EPC depth control / setpoint potentiometer, which is 8001.

4. 4

   Perform calibration sweep

   Follow the on-screen prompts to sweep the rotary switch through its full range of motion so the ECU can relearn the minimum and maximum voltage values.

5. 5

   Save calibration

   Save the calibration.

6. 6

   Replace component if calibration fails

   If the calibration fails (e.g., the terminal displays sub-fault F02 'Calibrated values are faulty' or F08 'Calibration taking too long'), the potentiometer itself has failed internally and the switch or armrest module must be replaced.