Fendt A.1.71 – A057: Steering Valve Supply Line Break

This code indicates a break in the steering valve electrical supply line. The steering controller is unable to communicate with or supply power to the Autoguide steering valve block due to an open circuit.

• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)

1. 1

   Test the wiring harness between the A057 steering controller ECU and the Y087 steering valve block for continuity and voltage.

2. 2

   Inspect the specific connector separation points on the Y087 valve block (X1588 and X1589) for corrosion, loose pins, or disconnected plugs.

3. 3

   Consult Fendt wiring diagram Sheets 38 / 39 to trace the exact pinouts for the electrical supply line.

1. 1

   Access the Valve Block

   Safely lift the tractor, remove the right rear wheel, and take off the side access panel to access the Y087 Steering valve block located on the right side of the transmission.

2. 2

   Visual Inspection

   Inspect the wiring harness leading to the Y087 valve block for obvious signs of chafing, breaks, or rodent damage.

3. 3

   Test Continuity

   Disconnect the harness at the Y087 valve block (connectors X1588/X1589) and at the A057 ECU. Use a multimeter to test for an open circuit (break) in the supply wires.

4. 4

   Repair the Harness

   If a break is found, repair the damaged section of the wiring harness using appropriate weatherproof splices, or replace the damaged connector pigtail.

5. 5

   Reassembly and Testing

   Reconnect all plugs, reinstall the access panel and the right rear wheel. Clear the fault codes via the tractor's terminal and test the Auto-Guide system to ensure the steering valve actuates properly without throwing code A.1.71.