Fendt A.1.2B – ECU, enhanced control (A002): Spool valve fault, valve 2 - Floating position is not reached.

The system detects that the main piston inside the spool valve cannot physically reach the commanded floating position. As a safety measure, the valve automatically moves into the neutral position and disables further operation of that specific hydraulic circuit.

• 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 (409, 410, 411, 412)
• Favorit 700 / 700 Vario (711, 712, 714, 716)
• Favorit 800 / 800 Vario (815, 817, 818)
• Favorit 900 / 900 Vario (916, 920, 924, 926, 930)
• COM III variants of the 300, 400, 700, 800, and 900 Vario series

1. 1

   Oil Quality & Contamination Check: Check the hydraulic oil for contamination. The most common cause for a spool valve failing to reach a position is dirt or foreign particles binding the main piston.

2. 2

   Hydraulic Oil Temperature: Ensure the oil is up to operating temperature. Extremely low hydraulic oil temperatures can cause sluggish spool movement, triggering a false position fault.

3. 3

   Control Pressure Test: Test the control pressure at port M5 and check the diaphragm accumulator (RV7/FP). A drop in pilot control pressure (below 22 bar) can prevent the valve from shifting fully.

4. 4

   Electrical / CAN Bus Inspection: Inspect connector X327 (the specific connector for Valve 2 / Y016) for corrosion, backed-out pins, or wiring damage. Verify that the supply voltage to the valve is stable (faults will also trigger if voltage drops below 8V or spikes above 18V/45V).

1. 1

   Preparation

   Park the tractor on a level surface, lower all hydraulic implements, turn off the engine, and relieve all hydraulic system pressure.

2. 2

   Access the Valve Block

   Locate the central control block. On most 700/800/900 Vario models, this is accessed by unscrewing the right-hand step and pulling the right auxiliary tank outwards.

3. 3

   Identify Y016

   The Y016 valve is the 2nd control valve slice on the underside of the central control block (often color-coded blue on the hydraulic remotes).

4. 4

   Clean the Area

   Thoroughly clean the exterior of the valve block to prevent dirt from entering the hydraulic system during disassembly.

5. 5

   Removal

   Disconnect the X327 electrical connector. Unbolt the tie rods holding the sandwich plate assembly together and carefully extract the Y016 valve slice.

6. 6

   Inspection/Cleaning

   Inspect the control block segments internally. If minor debris is found, clean the valve slice thoroughly. However, if the internal position sensor is faulty or the spool is scored, the valve slice cannot be serviced and must be replaced.

7. 7

   Installation

   Insert the new Bosch SB23 valve slice, ensuring all O-rings and seals are properly seated. Torque the tie rods to the manufacturer's specification.

8. 8

   Reassembly & Calibration

   Reconnect the X327 connector. Refit the auxiliary tank and steps.

9. 9

   Fluid Flush

   If contamination was the root cause, it is essential to change the hydraulic oil and high-pressure filters before operating the tractor to prevent immediate damage to the new valve.

10. 10

    EOL Programming

    Note that the auxiliary control valves are programmed for their specific positions in the End-of-Line (EOL) program. A dealer diagnostic tool (FENDIAS) may be required to teach-in the new valve to the A002 ECU.