Fendt 18.1.6A – A057 - ECU, Steering Controller (Autoguide): Y087 - Steering valve block, Autoguide

Supply voltage to the steering valve block has dropped below 10 V.

• 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 series (COM III generation)
• Fendt 400 Vario series (COM III generation)
• Fendt 700 Vario series (COM III generation)
• Fendt 800 Vario series (COM III generation)
• Fendt 900 Vario series (COM III generation)
• Fendt 500 Vario SCR / S4 generations
• Fendt 700 Vario SCR / S4 generations
• Fendt 800 Vario SCR / S4 generations
• Fendt 900 Vario SCR / S4 generations

1. 1

   System Voltage Check: Verify the tractor's battery and alternator are outputting a healthy 12V-14V.

2. 2

   Harness & Connector Inspection: Inspect the wiring harness leading to the Y087 steering valve block (typically located on the right side of the transmission) for corroded pins, loose connections, or chafed wires.

3. 3

   Supply Voltage Test: Disconnect the plug at the Y087 valve block and measure the supply voltage across the power and ground pins with the key on. It must be well above 10 V.

4. 4

   CAN Bus Check: Check the CAN bus lines at the valve. The total resistance across the CAN High and CAN Low pins should be 60 Ohms, and the voltage level of CAN High/CAN Low should be around 2.5V.

1. 1

   Resolve Wiring Issues

   If the voltage at the Y087 connector is below 10 V but the battery voltage is normal, trace the electrical supply line back to the steering controller (A057) and fuse board to locate and repair the break or high-resistance connection.

2. 2

   Access the Valve Block

   If the valve block itself has an internal short causing the voltage drop and needs replacement, safely support the tractor, remove the right rear wheel, and remove the access panel to reach the Y087 block.

3. 3

   Replace the Valve

   Clean the area thoroughly to prevent hydraulic contamination. Disconnect the hydraulic lines and electrical connectors. Unbolt the old Y087 steering valve block and install the new unit.

4. 4

   Reassemble and Bleed

   Reconnect all hydraulic lines and electrical plugs. Top off hydraulic fluid and bleed the steering system as per standard hydraulic procedures.

5. 5

   Calibration

   A newly installed steering valve block must be calibrated to the tractor's ECU. Using the Fendt terminal or FENDIAS diagnostic tool, run Calibration Code 2403 (Steering valve calibration).