Fendt A.1.45 – Enhanced Control ECU: Y018 - Spool valve fault, valve 4 — Overvoltage (> 45 volts)

The internal electronics of the auxiliary control valve 4 (Y018) are detecting an electrical voltage exceeding 45 volts. This points to a catastrophic failure of the valve's internal circuit board/sensor or a severe short circuit, causing the ECU to force the valve into the neutral position.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• Farmer 400 Vario
• Favorit 700 Vario
• Favorit 900 Vario
• 300 Vario Series
• 400 Vario Series
• 500 Vario Series
• 700 Vario Series
• 800 Vario Series
• 900 Vario Series

1. 1

   Check system voltage to verify the tractor's alternator is not severely overcharging the system.

2. 2

   Inspect connector X329 on Valve 4 (Y018) for corrosion, water ingress, or bent pins (specifically pins 23, 24, and 26).

3. 3

   Test harness voltage at the harness side of connector X329 with the key ON. If voltage is 12V-14V (internal valve failure cause), the valve's internal electronics have failed. If abnormally high (short circuit cause), trace the wiring harness back to the E-box for a short to power.

4. 4

   Verify the power supply for the CAN bus on circuit board A013 by checking fuses F040 and F041.

1. 1

   Preparation

   Turn off the tractor, relieve all hydraulic pressure, and disconnect the battery.

2. 2

   Access the Valve Block

   Depending on the model (e.g., 900 Vario), unscrew the right step and pull the right auxiliary fuel/air tank outwards to access the central control block.

3. 3

   Removal

   Disconnect the electrical connector (X329) from Valve 4 (Y018). Unbolt the tie rods/mounting bolts holding the valve slice to the hydraulic block. Carefully remove the valve, ensuring no dirt enters the hydraulic system.

4. 4

   Installation

   Install the new spool valve using new O-rings between the valve slices. Torque the mounting bolts to OEM specifications and reconnect connector X329.

5. 5

   Software Calibration

   Connect the FENDIAS diagnostic tool and use the EOL (End of Line) program to program the new auxiliary control valve for 'Position 4'.