Fendt A.1.3B – Comfort-BUS / Electrical Auxiliary Control Valves: Spool valve fault, valve 3 — Floating position is not reached.

The main piston of electrical spool valve 3 (designated as the "red" valve) is failing to reach its designated floating position. As a safety measure, the system forces the valve to move into the neutral position and locks it, disabling the valve's operation.

• 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
• Fendt 400 Vario series
• Fendt 700 Vario series
• 714
• 716
• 718
• 720
• 722
• 724
• Fendt 800 Vario series
• Fendt 900 Vario series
• 916
• 920
• 924
• 926
• 930
• 936

1. 1

   Inspect the valve actuator for mechanical binding. The manual actuation mechanism must not have any play, and the slider/actuator must be able to return to the center (neutral) position by itself.

2. 2

   Check the hydraulic oil filters and inspect the oil for debris or contamination, which is a primary cause of spool valves failing to reach their commanded positions.

3. 3

   Check the wiring harness and CAN II pins 4 and 5 for proper communication to rule out an internal position sensor fault or a magnet output stage fault within the spool valve.

4. 4

   Note that canceling a fault code on the terminal does not remove the fault; each stored code must be cleared individually, and it will return on the next startup if the physical issue persists.

1. 1

   Relieve Hydraulic Pressure

   Ensure the tractor is turned off and all hydraulic pressure is relieved from the system before servicing the valve block.

2. 2

   Clean the Valve Block

   Disassemble the affected spool valve (Valve 3 / Red). Thoroughly clean the valve block and the spool to remove any dirt, grime, or oil contamination.

3. 3

   Inspect the Spool

   Give the valve spool extra attention. It is critical that the spool has no scoring, scratches, or damage from high pressure or debris.

4. 4

   Rebuild or Replace

   If the spool is undamaged and the issue was merely contamination, rebuild the valve block using new O-rings and assembly grease. If the spool is scored, mechanically jammed, or if the internal position sensor/solenoid has failed, the spool valve assembly or the specific solenoid must be replaced.

5. 5

   Recalibrate

   After reassembly or replacement, the valve block may need to be recalibrated via the tractor's diagnostic terminal.