Fendt 09.1.49 – Hydraulics / Enhanced Control ECU: Y021 - Front pressure compensator lock valve (SA-DA switchover)

The system has detected a faulty lock valve or pressure compensator, typically caused by a short circuit to earth, a short circuit to +UB (battery voltage), or a break in the wiring. As a safety measure, the valve moves to neutral and locks, preventing the front power lift from raising or functioning correctly.

• 922 Vario COM III
• 924 Vario COM III
• 927 Vario COM III
• 930 Vario COM III
• 933 Vario COM III
• 936 Vario COM III
• Fendt 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III & SCR)
• Fendt 800 Vario (COM III & SCR)
• Fendt 900 Vario series (COM III & S4)
• Fendt 922
• Fendt 924
• Fendt 927
• Fendt 930
• Fendt 933
• Fendt 936
• Fendt 939

1. 1

   Locate Connector X332: This is the designated separation point/connector for the Y021 solenoid valve.

2. 2

   Wiring Inspection: Inspect the wiring harness leading to the Y021 valve for physical damage, chafing, or breaks.

3. 3

   Electrical Testing: Use a multimeter to check the signal line to the valve for continuity, short circuit to ground (Earth), and short circuit to power (+UB).

4. 4

   Solenoid Test: Test the resistance of the Y021 solenoid coil itself to determine if the coil has failed internally.

1. 1

   Locate the Valve

   The Y021 Front pressure compensator lock valve is located on the right side of the tractor, on the central valve block (for enhanced control hydraulics).

2. 2

   Access the Block

   Detach the metal cover panel/guard on the right side to gain access to the central valve block. (On some models, removing the right rear wheel makes access significantly easier).

3. 3

   Depressurize

   Ensure the tractor is turned off and the hydraulic system is fully depressurized before loosening any hydraulic fittings.

4. 4

   Disconnect

   Unplug the electrical connector (X332) from the Y021 solenoid valve.

5. 5

   Remove and Replace

   Unbolt the faulty Y021 lock valve from the central valve block. Install the new replacement valve, ensuring any O-rings or seals are properly seated and lubricated with clean hydraulic fluid.

6. 6

   Reassembly

   Reconnect the X332 electrical connector and reinstall the protective cover panel.

7. 7

   Clear and Test

   Turn on the ignition, clear the 09.1.49 fault code via the tractor's terminal or FENDIAS diagnostic tool, and test the front power lift (SA-DA switchover) to confirm the repair.