Fendt 9.1.D2 – A004 / A002: S021, S022 - External button front power lift 'raise' / 'lower' — Button double operation (button possibly stuck)

This fault code indicates a conflict in the external front power lift controls. The system is detecting simultaneous signals from both the 'raise' (S021) and 'lower' (S022) external pushbuttons, or it detects that one of the buttons is continuously engaged. This is most commonly caused by a button being physically stuck due to dirt/debris or an internal electrical short within the switch. As a safety consequence, the front power lift function is locked and cannot be operated.

• 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
• 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
• Farmer 400 Vario (409, 410, 411, 412)
• Favorit 700 Vario (711, 712, 714, 716)
• Favorit 900 Vario (916, 920, 924, 926, 930, 936, 939)
• Fendt 300 Vario series (including COM III and S4 generations)
• Fendt 400 Vario series (including COM III and S4 generations)
• Fendt 700 Vario series (including COM III and S4 generations)
• Fendt 800 Vario series (including COM III and S4 generations)
• Fendt 900 Vario series (including COM III and S4 generations)

1. 1

   Inspect the external front power lift buttons (S021 and S022) located on the front of the tractor for packed mud, ice, or debris that might be physically wedging the button in the depressed position.

2. 2

   Test the digital input voltage at the switch with the ignition ON. The signal should read approximately 3.7 VDC when not actuated, and drop to 1.8 VDC when actuated.

3. 3

   Refer to the Fendt circuit diagram 'Spool valves 2' (Sheet 27). Inspect the wiring harness leading to the front switches for chafing, pinched wires, or cross-shorts that could be bridging the raise and lower signal wires together.

4. 4

   Disconnect the switch and perform a continuity test with a multimeter. If the switch shows continuity across its terminals while resting (unpressed), the internal spring or contact has failed.

1. 1

   Power Down

   Turn the tractor ignition OFF and disconnect the battery ground to prevent electrical spikes.

2. 2

   Clean the Housing

   Thoroughly clean the area around the external front hitch switches to prevent dirt from falling into the electrical connectors. If the button was just jammed by debris, cleaning it and working it free with contact cleaner may resolve the issue.

3. 3

   Remove the Faulty Switch

   If the switch failed the continuity/voltage test, disconnect the wiring harness plug from the back of the affected switch (S021 or S022).

4. 4

   Dismount

   Unclip or unscrew the faulty switch from the front linkage housing bezel.

5. 5

   Install the New Part

   Snap the new OEM switch into the housing. Apply a small amount of dielectric grease to the electrical connector to prevent future moisture corrosion, and plug the harness back in.

6. 6

   Clear Codes and Test

   Reconnect the battery, turn the ignition ON, and clear the stored 9.1.D2 fault code from the terminal. Test the external raise and lower functions to ensure the front power lift operates smoothly without locking out.