Fendt 4.1.44 – Transmission Control Module: Engine speed Hall sensor 1 — Signal fault

The control unit is not receiving a valid, plausible speed signal from the primary engine speed Hall-effect sensor. This restricts functionality, forcing the machine into 'Auxiliary operation' (emergency mode) where only limited driving functions are 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
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• 924 Vario
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• 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 Vario
• Fendt Favorit 700 Vario
• Fendt Favorit 900 Vario
• Fendt 200 Vario
• Fendt 300 Vario
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• Fendt 500 Vario
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• Fendt 1000 Vario

1. 1

   Check the A013 fuse block (specifically fuse 4 or 11) for a blown 12V supply fuse, as a power supply fault is a primary cause.

2. 2

   Visually inspect the wiring harness and the connector at the B010 sensor for corrosion, moisture, or physical damage.

3. 3

   Using a multimeter, verify that the sensor is receiving its required 12V supply when the ignition is turned ON.

4. 4

   Verify the signal wire continuity from the B010 sensor back to the Transmission Control ECU to rule out a broken wire in the harness.

1. 1

   Park and secure the tractor.

   Park the tractor on a level surface, turn off the engine, engage the handbrake, and remove the key.

2. 2

   Test and replace the 12V supply fuse.

   Locate the A013 fuse panel and test the relevant 12V supply fuse (Fuse 4 or 11). Replace the fuse if it is blown. If the fuse blows again upon startup, trace the circuit for a short to ground.

3. 3

   Locate the sensor.

   Locate the B010 Engine speed Hall sensor 1 on the machine.

4. 4

   Disconnect the sensor.

   Disconnect the electrical plug from the sensor.

5. 5

   Diagnose internal sensor failure.

   If the wiring, connector, and 12V supply have all tested good, the Hall sensor itself has failed internally.

6. 6

   Remove the faulty sensor.

   Unbolt and remove the faulty B010 sensor from its mounting port.

7. 7

   Install the new sensor.

   Install the new OEM replacement sensor and torque to the manufacturer's specification.

8. 8

   Reconnect the harness.

   Reconnect the electrical harness, ensuring the plug clicks securely into place.

9. 9

   Clear the fault code.

   Turn on the ignition and use the tractor's terminal (or the FENDIAS diagnostic tool) to clear the stored 4.1.44 fault code.

10. 10

    Test drive the tractor.

    Start the tractor and perform a test drive to verify that the speed signal is restored and the tractor has successfully exited 'Auxiliary operation' (emergency mode).