Fendt 9.1.58 – A002 ECU, enhanced control: Spool valve fault on the Y019 Auxiliary control valve

The valve actuator does not return, or the main piston cannot return to its neutral position due to oil contamination or dirt causing the valve slide to jam.

• 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
• Farmer 400 Vario 410
• Farmer 400 Vario 411
• Farmer 400 Vario 412
• Favorit / Vario 711
• Favorit / Vario 712
• Favorit / Vario 714
• Favorit / Vario 715
• Favorit / Vario 716
• Favorit / Vario 717
• Favorit / Vario 815
• Favorit / Vario 817
• Favorit / Vario 818
• Favorit / Vario 916
• Favorit / Vario 920
• Favorit / Vario 924
• Favorit / Vario 926
• Favorit / Vario 930
• COM III Vario 300 series
• COM III Vario 400 series
• COM III Vario 700 series
• COM III Vario 800 series
• COM III Vario 900 series

1. 1

   Manual Actuation Test: Check the manual actuation of the Y019 spool valve. The manual actuation must not have play, and the slider must go into the middle (neutral) position by itself.

2. 2

   Hydraulic Fluid Inspection: Check the hydraulic oil for heavy dirt or contamination, which is the primary cause of the valve slide jamming.

3. 3

   System Pressure Check: Verify control pressure and system pressure at the measuring points (e.g., M5 for control pressure) to ensure no underlying hydraulic supply issues are preventing the valve from returning.

1. 1

   Locate the Valve

   The Y019 valve (often designated as Valve 5) is typically located on the underside of the central control block. On some models (like the 900 series), accessing it requires unscrewing the right step and pulling the right auxiliary tank outwards.

2. 2

   Clean and Inspect

   Remove the Y019 auxiliary control valve. Inspect the main piston and valve slide for scoring, debris, or sludge.

3. 3

   Flush the System

   If oil contamination is found, clean the spool valve thoroughly. You must also flush the hydraulic system and replace the hydraulic filters to prevent the dirt from immediately jamming the valve again.

4. 4

   Reassemble and Test

   Reinstall the cleaned valve. Verify that the slider returns to the neutral position freely.

5. 5

   Replace if Necessary

   If the valve slide is physically damaged, scored, or still jams after cleaning, the entire auxiliary control valve must be replaced.