Fendt A.1.6A – Overall system/tractor or Auto-Guide steering system (enhanced control ECU): Y087 - Steering valve block, Auto-Guide: Supply voltage < 10 V

The electrical supply voltage reaching the Auto-Guide steering valve block has dropped below the minimum required threshold of 10 volts, often due to a break in the electrical supply line, a short circuit, or a failing power source.

• 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) / Farmer 400
• Fendt 700 Vario (COM III) / Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III) / Favorit 900 (Models 919 through 934)

1. 1

   Check the electrical supply line to the steering valve for breaks or shorts (refer to wiring diagram Sheet 38 / 39)

2. 2

   Inspect the electrical connectors at separation points X1588 and X1589 on the Y087 valve block for corrosion or loose pins

3. 3

   Test CAN Bus total resistance (should be 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 indicates a short to ground; 4 VDC and higher indicates a short circuit to positive)

1. 1

   Access the Valve Block

   The Y087 steering valve block is located on the right side of the transmission.

2. 2

   Remove Obstructions

   Remove the right rear wheel and the right-side panel to gain physical access to the valve block.

3. 3

   Inspect and Repair Wiring

   Disconnect separation points X1588 and X1589. Test the harness for continuity and voltage drop. Repair any broken wires or replace the damaged harness section.

4. 4

   Replace the Valve (if necessary)

   If the wiring is intact and providing proper voltage from the source, but the voltage drops when connected (indicating an internal short in the valve), the Y087 steering valve block must be replaced.

5. 5

   Reassembly

   Reconnect the electrical separation points, reinstall the side panel, and remount the right rear wheel.

6. 6

   Calibration

   If the steering valve block was replaced, the new valve must be calibrated. Enter calibration mode and use Calibration code "2403" to calibrate the new Y087 steering valve.