Fendt 08.1.FC – A050 ECU (Basic Control Unit): Y077 - EHR cut-off valve, rear (Manual actuation)

A manual actuation fault occurs when the valve is deflected from its neutral position. As a safety consequence, the system locks the valve and turns the pilot pressure OFF.

• 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)
• FENDT 800 Vario (COM III)
• FENDT 900 Vario (COM III)
• FENDT 919 Vario (COM III)
• FENDT 922 Vario (COM III)
• FENDT 924 Vario (COM III)
• FENDT 927 Vario (COM III)
• FENDT 930 Vario (COM III)
• FENDT 933 Vario (COM III)
• FENDT 936 Vario (COM III)

1. 1

   Visually inspect the Y077 valve on the rear valve block to check if it has been manually actuated or physically deflected from its neutral position.

2. 2

   Check the pilot control actuator for physical jamming or debris that might prevent the spool from returning to neutral.

3. 3

   Using a multimeter, check the voltage at the Y077 valve connector (should be 12-14 VDC when unlocked/active, and 0 VDC when locked/inactive).

4. 4

   Use the FENDIAS diagnostic tool to check for accompanying A050 ECU faults (like 08.1.A0 or 08.1.A1) which indicate an EEPROM memory failure rather than a mechanical valve failure.

1. 1

   Access the valve

   Park the tractor on a level surface, turn off the engine, and relieve all hydraulic pressure. Go to the rear of the tractor and detach the rear valve block cover panel to access the Y077 EHR cut-off valve.

2. 2

   Clear mechanical jam

   If the valve is mechanically jammed, carefully remove the actuator housing and inspect the spool. Clean any hydraulic debris or contamination.

3. 3

   Reset the valve

   If the valve was manually actuated, return it to its neutral position.

4. 4

   Replace the valve

   If the internal return spring is broken, the spool is scored, or the solenoid coil fails electrical testing, replace the Y077 valve. Disconnect the electrical harness, unbolt the valve from the rear block, and install the new valve with fresh O-rings.

5. 5

   Software reset

   Reconnect the battery, turn the ignition on, and connect the FENDIAS tool. Clear the 08.1.FC fault code.

6. 6

   Calibration and testing

   Run the tractor and test the rear power lift / EHR controls to ensure the pilot pressure is restored and the valve no longer locks out.