Fendt A.1.1B – Enhanced Control Unit (ECU A002): Spool valve fault, valve 1 — Floating position is not reached.

The auxiliary control valve 1 (designated as the 'yellow' valve) has failed to physically reach the commanded floating position. This is often caused by mechanical jamming of the pilot control actuator or main piston, frequently due to hydraulic oil contamination. 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
• Farmer 400 series
• Favorit 700 and 900 series
• Fendt 300 Vario
• Fendt 400 Vario
• Fendt 700 Vario
• Fendt 800 Vario
• Fendt 900 Vario
• 409-412 Vario
• 711-724 Vario
• 815-828 Vario
• 916-936 Vario

1. 1

   Inspect for Contamination: Check the hydraulic oil for contamination, which is a primary cause of the main piston or pilot actuator jamming.

2. 2

   Electrical & CAN Bus Check: Verify the integrity of connector X326. Check for proper supply voltage (must be between 8V and 18V).

3. 3

   Pressure Tests: Check the control pressure at measurement point M5 to ensure it has not dropped below 22 bar. Test the diaphragm accumulator and RV7/FP valves.

4. 4

   Internal Sensor Check: Determine if the fault is purely mechanical or if the internal position sensor / magnet output stage within the spool valve has failed.

1. 1

   Relieve Pressure

   Safely relieve all hydraulic pressure from the system before servicing the valve block.

2. 2

   Disconnect

   Unplug the electrical connector X326 from Valve 1 (Y015).

3. 3

   Remove/Replace

   If the valve is jammed due to severe contamination or has a failed internal position sensor, remove the Y015 spool valve from the central control block and install the replacement.

4. 4

   EOL Programming

   The new auxiliary control valve must be programmed specifically for 'Position 1' using the Fendt EOL (End of Line) program. The tractor will not recognize the valve's physical position on the block without this programming.

5. 5

   Calibration

   Calibrate the linear modules for the hydraulic auxiliary spool valves (Calibration codes 1003–1006) and the crossgate lever (Calibration code 1001) using the tractor's terminal.

6. 6

   Clear Codes

   Clear the stored A.1.1B fault code from the ECU memory using the Fendt-EST / SERDIA diagnostic tool.