Fendt 04.1.A5 – A050 Basic Control Unit ECU: Initial reference (= zero position) could not be found or reached during ignition "ON"

Initial reference (= zero position) could not be found or reached during ignition "ON". The tractor will allow continuation in emergency mode.

• 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
• 409 Vario COM III
• 410 Vario COM III
• 411 Vario COM III
• 412 Vario COM III
• 711 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 815 Vario COM III
• 817 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• 824 Vario COM III
• 828 Vario COM III
• 916 Vario COM III / S4
• 920 Vario COM III / S4
• 926 Vario COM III / S4
• 939 Vario COM III / S4

1. 1

   Check the ease of movement of the adjustment device using the emergency control system (a binding transmission control shaft can prevent the actuator from finding its zero position)

2. 2

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

3. 3

   Verify if the neutral points of the transmission control for forward and reverse movement are too far apart (greater than 8°)

4. 4

   Check if the maximum transmission ratio points can be found (Forward: minimum 155°, maximum 187°; Reverse: minimum 136°, maximum 165°)

5. 5

   Check the 'Transmission control' circuit diagram for wiring faults, CAN-bus communication errors, or a blown fuse on the A013 PCB microfuse board

1. 1

   Safely park the machine and turn the ignition OFF.

   Ensure the machine is safely parked before beginning the repair.

2. 2

   Access the Vario transmission control housing.

   Locate and access the transmission control housing to reach the internal components.

3. 3

   Remove the connecting rod and the actuator shaft.

   Disconnect the mechanical linkage components.

4. 4

   Dismantle the control housing if necessary.

   Dismantle the housing to access the internal linkage if required.

5. 5

   Remove the faulty A009 actuator unit.

   Extract the failed actuator unit from the assembly.

6. 6

   Install the new A009 actuator unit.

   Install the replacement unit and reassemble the actuator shaft and connecting rod.

7. 7

   Top up the transmission oil.

   Add STOU 10W-40 or 15W-40 transmission oil if any was lost during the procedure.

8. 8

   Perform a Teach-In / Calibration procedure.

   Use the Fendt diagnostic terminal (Variotronic Ti) to allow the A050 ECU to learn the new actuator's zero position and maximum forward/reverse angles.