Fendt 4.1.A3 – Transmission Control Unit (TCU): Fault or logical error in incremental sensor signal (actual position signal)

The incremental encoder is a position sensor located inside the A009 actuator unit that provides feedback on the actual transmission adjustment (ratio) to the control system. When this signal fails or is illogical, the system cannot accurately verify the transmission's physical adjustment.

• 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
• Fendt Farmer 400
• Fendt Favorit 700
• Fendt Favorit 900
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)

1. 1

   Check the ease of movement of the adjustment device using the emergency control system

2. 2

   Inspect the mechanical connection between the A009 actuator unit and the actuator shaft

3. 3

   Consult the Transmission Control electric/circuit diagram to verify the wiring integrity between the Transmission Control Unit and the A009 incremental sensor

1. 1

   Engage Emergency Mode

   If the tractor is immobilized, utilize the mechanical adjustment of the A009 actuator unit (emergency actuation) to safely move the tractor to a workshop.

2. 2

   Inspect the Actuator Unit (A009)

   The A009 unit controls the actuator shaft to change the transmission ratio in the ML transmission. It consists of a 12 V DC electric motor, a planetary gear, a clutch, the emergency drive, and the incremental encoder.

3. 3

   Verify Mechanical Linkage

   Ensure the actuator shaft is not binding and that the A009 unit is properly seated and connected to the shaft.

4. 4

   Test the Sensor

   Check the voltage and signal output from the incremental encoder to the Transmission Control Unit based on the wiring diagram.

5. 5

   Replace Component

   If the wiring is intact and the mechanical linkage moves freely but the signal remains faulty, the incremental encoder has failed. Replace the sensor or the complete A009 actuator unit.