Fendt 04.1.A6 – Transmission Control System: A009 - Actuator unit / Transmission control unit: Reference point signal fault during operation.

The A009 actuator unit (which physically shifts the transmission ratio) has lost its reference point (zero position) signal while the tractor is operating. When the reference signal is lost or faulty, the transmission cannot accurately determine the actuator's position. The tractor will restrict normal operation, but continuation in emergency mode is possible.

• 309 Vario COM III
• 310 Vario COM III
• 311 Vario COM III
• 312 Vario COM III
• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• 300 Vario (COM III)
• 400 Vario (COM III)
• 700 Vario (COM III, S4)
• 800 Vario (COM III, S4)
• 900 Vario (COM III, S4)
• 1000 Vario (S4)

1. 1

   Use the emergency control system to manually adjust the A009 actuator unit and check for ease of movement to ensure the transmission is not mechanically bound.

2. 2

   Verify the CAN bus wiring and terminating resistors between the A013 circuit board and the A009 actuator unit for communication drops.

3. 3

   Access the tractor diagnostics terminal (A008) and navigate to the transmission adjustment screen. Compare the VE (feedback from encoder) value to the REAL (actual transmission adjustment) value. If VE is erratic, missing, or deviates significantly, the incremental encoder is likely faulty.

1. 1

   Safely park the machine, turn off the ignition, and relieve hydraulic pressure.

2. 2

   Locate the A009 actuator unit on the side of the Vario transmission housing.

3. 3

   Disconnect the CAN bus and power wiring harnesses from the A009 unit.

4. 4

   Remove the connecting rod and actuator shaft linking the A009 unit to the transmission control housing.

5. 5

   Unbolt and remove the A009 actuator unit.

6. 6

   Install the new or repaired A009 actuator unit.

   Ensure the slip clutch (rated 2.5 to 3.5 Nm) and actuator shaft are properly aligned.

7. 7

   Reconnect the connecting rod and wiring harnesses.

8. 8

   Top up the transmission oil (STOU 10W-40) if any was lost during removal.

9. 9

   Turn the ignition on.

   The A009 actuator unit must run an initialization sequence to locate its reference point (approximate neutral position).

10. 10

    Clear the 04.1.A6 fault code from the memory using the terminal.