Fendt 0A.1.D5 – Hydraulic Control Module / Central Electrical System: S022 - Switch (external), lower front power lift

The system has detected a 'Signal fault' or a 'Faulty button' for the external lower front power lift switch (S022), typically due to a stuck contact or a short/open circuit in the switch wiring. The external lower button becomes inoperable until the next trouble-free cold start, and the associated hydraulic valve defaults to the neutral position.

• 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 Series
• 400 Vario Series (409, 410, 411, 412)
• 700 Vario Series (711, 712, 714, 715, 716, 717)
• 800 Vario Series (815, 817, 818)
• 900 Vario Series (916, 920, 922, 924, 926, 927, 930, 933, 936)

1. 1

   Inspect the S022 external pushbutton for physical damage, packed dirt, or moisture ingress that could cause the button to physically stick.

2. 2

   Disconnect the switch and inspect the wiring harness for chafing, breaks, or corrosion at the connector pins.

3. 3

   Use a multimeter to test the S022 switch for continuity to verify the circuit is open when released and closed when pressed.

4. 4

   Perform a cold start (key off, battery power cycled) to see if the fault clears after cleaning or manipulating the switch.

1. 1

   Power Down

   Turn off the tractor engine, apply the parking brake, and disconnect the battery to prevent accidental hydraulic actuation or electrical shorts.

2. 2

   Access the Switch

   Locate the external front power lift control panel on the front chassis/linkage area.

3. 3

   Removal

   Disconnect the electrical pigtail/connector from the rear of the S022 'Lower' switch. Depress the retaining tabs or remove the mounting screws securing the switch to the housing, and pull the faulty switch out.

4. 4

   Installation

   Push the new OEM switch into the housing until it clicks or secure it with the original fasteners.

5. 5

   Reconnection

   Apply a small amount of dielectric grease to the connector to prevent future moisture ingress, then plug the wiring harness back into the switch.

6. 6

   Testing

   Reconnect the battery. Perform a cold start to initialize the modules. Test the external front power lift buttons (both S021 Raise and S022 Lower) to ensure the linkage moves correctly and the 0A.1.D5 code does not return.