Fendt 0A.1.FB – Main Tractor Electronic Control Unit (ECU) / Basic Control Unit (A050 or A002 Enhanced Control ECU): S068 - Switch (external), valve actuation, lower

This fault code indicates a signal fault or a faulty button on the external lower valve actuation switch (designated as component S068). The system has detected an invalid signal, a broken wire, or a short circuit on the signal line. The external valve actuation button is rendered inoperable until the next trouble-free cold start.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 200 V, F, P Vario
• 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, S4, Gen6)

1. 1

   Inspect the S068 external lower valve actuation switch on the rear fender for physical damage, sticking, or debris.

2. 2

   Check for double actuation by ensuring the 'raise' switch (S067) is not also stuck.

3. 3

   Test the S068 switch for electrical continuity and proper operation when pressed (note that this operates on a 16V system).

4. 4

   Inspect the wiring harness and signal line between the S068 switch and the ECU for breaks, chafing, short circuits to ground, or connector corrosion.

1. 1

   Disconnect the tractor's battery before beginning electrical repairs.

2. 2

   Remove the faulty S068 external lower valve actuation switch from the fender/external control panel.

3. 3

   Disconnect the wiring harness connector from the switch.

4. 4

   If the wiring harness is damaged, repair the broken/shorted wires or replace the affected harness section.

5. 5

   If the switch is faulty, install a new OEM external lower valve actuation switch.

6. 6

   Reconnect the wiring harness and secure the switch in the mounting panel.

7. 7

   Reconnect the battery.

8. 8

   Perform a 'trouble-free cold start' (restart the tractor).

   The system requires a clean restart without the fault present to clear the inoperable state and reset the fault code.

9. 9

   Test the external valve actuation to ensure proper lowering functionality.