Fendt 4.1.31 – Transmission Control Module (EST / Transmission ECU): B014 Hall sensor for accumulator shaft direction - Signal fault / Signal failure

The transmission control module is not receiving a valid speed or directional signal from the B014 Hall sensor located on the accumulator shaft (hydrostat) inside the Vario transmission. The tractor will typically restrict functionality, though continuation in emergency mode (Auxiliary Operation) is usually possible.

• 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
• 207
• 208
• 209
• 210
• 211 (V/F/P)
• 309
• 310
• 311
• 312
• 313
• Farmer 400
• 409
• 410
• 411
• 412
• 413
• 414
• 415
• 500 Vario Series
• Favorit 700
• 711
• 712
• 714
• 716
• 720
• 815
• 817
• 818
• 822
• 824
• 826
• 828
• Favorit 900
• 916
• 920
• 924
• 926
• 930
• 936

1. 1

   Check Power Supply: Verify the 8.5 V supply to the sensor. Depending on the tractor model, this is typically routed through fuse A013 fuse 1 or A013 fuse 16.

2. 2

   Terminal Diagnostics (Variotronic Ti): Use the tractor's terminal (A008) to access the transmission diagnostics menu. Compare IDEAL, VE, and REAL values. A missing or erratic "REAL" value confirms a B014 sensor or wiring failure.

3. 3

   Wiring Inspection: Check the wiring harness and connector at the B014 sensor for corrosion, breaks, or shorts. Refer to the "Transmission" wiring diagram (often Sheet 22 or 29 depending on the series).

1. 1

   Safely park the tractor

   Safely park the tractor, apply the handbrake, and turn the ignition OFF.

2. 2

   Locate the sensor

   Locate the B014 hydrostatic collecting shaft sensor on the Vario transmission insert.

3. 3

   Disconnect the sensor

   Disconnect the electrical connector from the sensor.

4. 4

   Remove the old sensor

   Remove the retaining hardware and extract the old B014 sensor from the transmission housing.

5. 5

   Install the new sensor

   Install the new B014 sensor (Section 3.5.10 in the 800/900 series manual: "Install B014 hydrostatic collecting shaft sensor").

6. 6

   Reconnect the harness

   Reconnect the electrical harness.

7. 7

   Clear fault codes

   Turn the ignition ON and use the terminal to confirm and clear the fault codes.

8. 8

   Perform transmission calibration

   A transmission calibration may be required after replacing speed/direction sensors on the Vario insert to ensure the "REAL" and "IDEAL" values sync properly.