Fendt A.1.37 – Enhanced Control Unit (ECU) / Electric Auxiliary Control Valves: Y017 - Spool valve fault, valve 3 — Internal position sensor fault

The internal position sensor inside the auxiliary control valve has failed or is sending an implausible signal to the control unit. As a direct safety consequence, the system forces the valve into the neutral position and disables its operation to prevent undefined or uncontrolled hydraulic functions.

• 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
• Farmer 400 Vario series
• Favorit 700 Vario series
• Favorit 900 / 900 Vario series
• 916
• 920
• 924
• 926
• 928
• 930
• 800 Vario series
• 815
• 817
• 818

1. 1

   Verify the active fault code A.1.37 using the FENDIAS diagnostic tool or the tractor's Variotronic terminal.

2. 2

   Inspect the electrical harness and connector X328 at the Y017 valve for corrosion, moisture, or damaged pins.

3. 3

   Check hydraulic oil quality for severe contamination or degraded viscosity, which can cause the main piston to stick.

4. 4

   Ensure the hydraulic control pressure has not dropped below 22 bar.

1. 1

   Depressurize the System

   Turn off the tractor and relieve all hydraulic pressure from the system before beginning work.

2. 2

   Locate Valve 3 (Y017)

   Locate the central control block. Depending on the tractor model (e.g., 900 Vario), this may require unscrewing the right step and pulling the right auxiliary tank outwards to access the underside of the control block. Identify Valve 3 (Red).

3. 3

   Disconnect

   Unplug the X328 electrical connector from the Y017 valve.

4. 4

   Remove the Valve

   Unbolt the faulty auxiliary control valve from the hydraulic distributor block. Have a catch pan ready for residual hydraulic fluid.

5. 5

   Install the New Valve

   Mount the replacement spool valve, ensuring all O-rings/seals are properly seated. Torque the mounting bolts to the manufacturer's specifications.

6. 6

   Reconnect

   Plug the X328 connector back into the new valve.

7. 7

   EOL Programming (Crucial)

   You cannot simply plug and play. Once the new spool valve is installed, you must use the FENDIAS diagnostic tool to perform an EOL (End of Line) programming / Teach-in process. This assigns the new valve to "Position 3" so the ECU recognizes it and calibrates its neutral position.

8. 8

   Clear Codes and Test

   Clear the A.1.37 fault code from the memory and test the hydraulic function to ensure smooth operation.