Fendt 18.1.35 – A050 (ECU, basic control unit): Y087 - Steering valve block, Auto-Guide: Error with steering valve hardware.

This code indicates a physical hardware failure or internal fault within the electrohydraulic steering valve block (designated as component Y087) which is responsible for the tractor's Auto-Guide (or VarioGuide) automated steering system.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III and S4 Series)
• Fendt 800 Vario (COM III and S4 Series)
• Fendt 900 Vario (COM III and S4 Series)
• Fendt 1000 Vario (S4 Series)

1. 1

   Verify the electrical supply line voltage to the steering valve (must not drop below 10V or spike above 32V).

2. 2

   Inspect the wiring of the position sensor integrated into the steering valve for broken wires or short circuits.

3. 3

   Test the total resistance of the CAN bus at the valve connector (should read 60 Ohms; 120 Ohms indicates a wiring break or defective terminating resistor).

4. 4

   Check CAN High/CAN Low voltage levels (0 VDC = earth connection, 4 VDC or higher = short circuit to positive).

5. 5

   Verify if the steering actuator is physically jammed and unable to reach the neutral position during operation or run-up.

1. 1

   Depressurize the Hydraulic System

   Manually relieve the hydraulic pressure before performing any repairs to prevent severe injury, as the pressure pipes and accumulators connected to the central control block are pressurized up to 200 bar even with the engine off.

2. 2

   Access the Valve Block

   Remove the right rear wheel and the side panel to gain access to the Y087 steering valve block and its separation points (X1588 / X1589), located on the right side of the transmission on larger models.

3. 3

   Remove the Faulty Valve

   Disconnect the CAN bus electrical connectors and the hydraulic lines (Load Sensing, Pressure, and Tank lines) from the Y087 valve block. Unbolt the valve block from its mounting bracket.

4. 4

   Install the New Valve

   Mount the replacement steering valve block. Reconnect all hydraulic lines securely and plug in the electrical connectors.

5. 5

   Reassembly

   Reinstall the side panel and the right rear wheel.

6. 6

   Calibration

   Perform the VarioGuide steering valve calibration via the tractor's terminal using Calibration Code '2403'.