Fendt A.1.47 – ECU, enhanced control, electric auxiliary control valves: Y018 - Spool valve fault, valve 4 — Internal position sensor fault.

The internal sensor that monitors the physical position of the main piston inside auxiliary control valve 4 (Y018) has failed, lost communication, or is providing an implausible signal. As a built-in safety measure, the system automatically forces the valve into the neutral position and disables its operation.

• 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
• Fendt 300, 400, 700, 800, and 900 Vario series (COM III)
• Fendt Favorit 700 and Favorit 900 series
• Fendt Farmer 400 series

1. 1

   Inspect the wiring harness and the specific electrical connector for Valve 4 (X329) for corrosion, broken wires, or a loose connection.

2. 2

   Check the hydraulic oil for severe contamination, which can occasionally interfere with the sensor's reading mechanism.

3. 3

   Connect a diagnostic tool (FENDIAS or Jaltest AGV) to read live data from Valve 4 to confirm if the sensor value is dead or erratic.

1. 1

   Preparation

   Turn off the tractor, disconnect the battery, and relieve all hydraulic pressure from the system.

2. 2

   Locate the Valve

   Locate auxiliary control valve 4 (Y018) on the hydraulic valve block. Fendt often color-codes this specific valve position Green.

3. 3

   Removal

   Disconnect the X329 electrical connector. Unbolt the faulty spool valve (or the electronic actuator head, depending on the exact block design) from the central control block.

4. 4

   Installation

   Install the new replacement spool valve slice/actuator, ensuring O-rings are seated correctly, and torque the mounting bolts to OEM specifications. Reconnect the X329 wiring harness.

5. 5

   EOL Programming

   Using a diagnostic tool (FENDIAS, Jaltest, etc.), perform an EOL (End of Line) programming/Teach-in procedure. The new spool valve must be assigned to 'Position 4' on the CAN bus so the ECU recognizes it and calibrates its neutral position.

6. 6

   Testing

   Clear the A.1.47 fault code, start the tractor, and test the hydraulic remote to ensure full functionality.