Fendt 18.1.31 – MFA (Multifunction Armrest) / OVERALL SYSTEM/TRACTOR: Error with supply voltage from the steering valve (Y087)

The system is detecting an incorrect or missing electrical supply voltage to the Autoguide steering valve block (Y087). This can prevent the automated steering system from functioning properly and may trigger a warning or lockout of the Autoguide features.

• 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 700 Vario COM III series
• Fendt 800 Vario COM III series
• Fendt 900 Vario COM III series
• 916
• 920
• 922
• 924
• 926
• 930

1. 1

   Measure the supply voltage (positive and earth/ground) directly at the Y087 steering valve block harness connector (typically 12V; faults trigger if below 8V or above 18V)

2. 2

   Inspect CAN bus wiring by testing total resistance (should be ~60 Ohms; 120 Ohms indicates a break or defective terminating resistor)

3. 3

   Check the voltage level of CAN High and CAN Low (0 VDC indicates a short to ground, 4 VDC or higher indicates a short to positive)

4. 4

   Verify the wiring of the position sensor integrated into the steering valve for any breaks, chafing, or corrosion

5. 5

   Check if the steering valve needs to be recalibrated (Calibration code 2403) as voltage or communication errors can be tied to a loss of calibration

1. 1

   Resolve Wiring Issues

   If the diagnostic checks reveal a short, break, or poor ground in the harness leading to the Y087 valve block, repair the wiring or replace the damaged connector.

2. 2

   Replace the Valve Block

   If the wiring and CAN bus check out perfectly but the valve block still registers a supply voltage error or is physically stuck/unresponsive, the Y087 steering valve block must be replaced. Relieve hydraulic pressure and disconnect the hydraulic lines (Pressure, Tank, LS-OUT, LS ORBITROL, Right/Left Cylinder lines). Unbolt the defective valve block from its mounting bracket and install the new unit. Reconnect all hydraulic lines to their correct ports and plug in the electrical harness.

3. 3

   Perform System Calibration

   After repairing the wiring or replacing the Y087 valve, you must calibrate the Autoguide steering valve using the tractor's terminal. Enter Calibration Code 2403 (Autoguide steering valve) into the system and start the calibration process. Warning: The calibration runs automatically. The front wheels may move left and right on their own. Do not touch the steering wheel and do not leave the driver's seat (the seat switch must remain engaged) during this process. Wait for the terminal to display 'OK'. Turn the ignition key to position '0' and wait at least 15 seconds before turning it back on to save the new settings.