Fendt A.1.45 – A002 - ECU, enhanced control: Spool valve fault, valve 4 – Overvoltage (> 45 Volt)

An overvoltage condition forces the Y018 valve actuator (Auxiliary control valve, position 4, green) to immediately move into the neutral position, disabling the hydraulic function for that specific remote.

• 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
• Farmer 400 Vario
• Favorit 700 and 900 Vario
• 300, 400, 500, 700, 800, and 900 Vario Series (including COM II, COM III, SCR, and S4 generations)

1. 1

   System Voltage Check: Test the tractor's overall system voltage at the battery and alternator while running to verify if the alternator voltage regulator has failed (reading > 45V).

2. 2

   Harness & Connector Inspection: Locate connector X329 (pins 24, 26) supplying the Y018 green valve and inspect the wiring harness for shorts to other power sources.

3. 3

   Internal Valve Failure: If the system voltage is normal (approx. 12-14V) but the code persists, verify if the internal circuit board/magnet output stage within the Y018 spool valve has failed and is falsely reporting an overvoltage condition.

1. 1

   Preparation

   Lower all hydraulic implements to the ground. Turn off the engine, cycle the hydraulic levers/terminal buttons to relieve any residual hydraulic pressure, and disconnect the tractor's battery.

2. 2

   Access the Valve Block

   Locate the rear hydraulic valve stack. Identify the Y018 valve (Position 4, associated with the green remote couplers).

3. 3

   Disconnection

   Unplug the X329 electrical connector from the Y018 valve.

4. 4

   Removal

   Remove the tie-rods/through-bolts that hold the hydraulic valve stack together. Carefully slide out the faulty Y018 green valve slice.

5. 5

   Installation

   Install the new spool valve slice, ensuring all O-rings and mating seals between the slices are new and properly seated.

6. 6

   Reassembly

   Reinsert the tie-rods and torque them to the manufacturer's specification to prevent leaks. Reconnect the X329 electrical connector.

7. 7

   Calibration / EOL Programming

   Program the auxiliary control valve for its specific position (Position 4) using the Fendt EOL (End of Line) program via the FENDIAS diagnostic tool so the A002 ECU recognizes it on the CAN bus.