Fendt 18.1.34 – Electrohydraulic Steering / Way-line guidance system (A057 / A050): Y087 - Steering valve block, Auto-Guide: Error with steering valve actuation.

A malfunction in the proportional steering valve (component Y087) that controls the automated steering system (Auto-Guide / VarioGuide). The system has detected that the valve is not actuating correctly when commanded, which will disable the automated steering functionality.

• 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
• Fendt 400 Vario
• Fendt 700 Vario
• Fendt 800 Vario
• Fendt 900 Vario
• 916
• 922
• 924
• 927
• 930
• 933
• 936
• 939

1. 1

   Inspect the electrical supply line to the Y087 steering valve for breaks, chafing, or corrosion, specifically checking separation points/connectors X1588 and X1589.

2. 2

   Check the supply voltage to the CAN bus consumers (positive and earth).

3. 3

   Test the total resistance of the CAN bus. It should read 60 Ohms. A reading of 120 Ohms indicates a wiring break or a defective terminating resistor.

4. 4

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

5. 5

   Verify if there is a mechanical bind on the steering actuator or a failure of the internal position sensor within the valve block.

1. 1

   Access the Valve

   On most heavy Fendt models (like the 900 Vario series), the Y087 valve block is located on the right side of the transmission. Remove the right rear wheel and the side panel to access the electro-hydraulic steering connection plate (APLE).

2. 2

   Depressurize

   Ensure the tractor is off and hydraulic system pressure is fully relieved before cracking any lines.

3. 3

   Removal

   Disconnect the electrical connectors (X1588, X1589) from the Y087 proportional valve. Disconnect and cap the hydraulic lines to prevent contamination. Unbolt the valve block from the mounting plate.

4. 4

   Installation

   Mount the new Y087 steering valve block. Reconnect the hydraulic lines and electrical connectors.

5. 5

   Bleed the System

   Start the tractor and cycle the steering manually to bleed air from the hydraulic steering circuit.

6. 6

   Calibration

   Enter Calibration Code 2403 via the tractor's terminal to teach the system the new valve's parameters. A new steering valve will not work out of the box without this critical step.