Fendt 9.1.B1 – A004 (Control Console / ECU control panel) or A039 (MFA, multifunction armrest): Signal line fault, Sensor out of position, or Sensor fault in B040 - Sensor, front power lift position

Triggered by component B040 - Sensor, front power lift position. Indicates a Signal line fault, Sensor out of position, or general Sensor fault. Can also be caused by an 8.5 V supply fault to the sensor. Consequence: No position control available for the front power lift (front hitch). The system may default to allowing operation only via external buttons without automatic position control.

• 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 Farmer 400 series
• Fendt Favorit 700 and 900 series
• Fendt 300 Vario
• Fendt 400 Vario
• Fendt 700 Vario
• Fendt 800 Vario
• Fendt 900 Vario (including COM III and S4 generations)

1. 1

   Check Power Supply: Verify the 8.5 V reference voltage supply to the B040 sensor (often protected by fuse A013 - Fuse 11 or Fuse 12, depending on the exact model).

2. 2

   Inspect Wiring: Check the signal line and ground wire between the B040 sensor and the control module for continuity, shorts to ground, or breaks.

3. 3

   Physical Inspection: Check if the sensor is physically 'out of position'. Inspect the mechanical linkage connecting the front hitch to the rotary sensor to ensure it hasn't slipped, bent, or disconnected.

1. 1

   Secure the Machine

   Lower the front power lift to the ground (if possible) and turn off the tractor.

2. 2

   Locate the Sensor

   Locate the B040 position sensor on the front power lift assembly.

3. 3

   Test the Circuit

   Disconnect the sensor harness. Turn the ignition ON and use a multimeter to verify the 8.5 VDC supply at the connector. If voltage is missing, replace the blown fuse or repair the broken supply wire.

4. 4

   Replace the Sensor

   If the wiring and voltage are intact but the signal is still faulty or out of range, remove the mounting hardware and linkage arm from the old sensor, and install the new sensor.

5. 5

   Calibrate the System

   Calibrate the front power lift using the tractor's terminal or FENDIAS software. The specific calibration codes for the front power lift are '9001' (for the depth control setpoint potentiometer) and '9002' (for the B040 position sensor itself).