Fendt 08.1.F4 – A050 ECU (Basic Control Unit): Y077 - EHR cut-off valve, rear (Valve actuator falls short)

The valve spool failed to reach its commanded position, causing the system to force the valve to the neutral position and lock it, disabling the rear power lift. This is frequently caused by brief control pressure dips in the hydraulic system or hydraulic oil that is too viscous at very low ambient temperatures.

• 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 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

   Run the tractor until the hydraulic oil reaches normal operating temperature (40–50°C) to check if cold, viscous oil is causing the fault

2. 2

   Perform a hydraulic pilot pressure test to monitor for brief pressure drops or supply issues to the rear valve block when hydraulic functions are actuated

3. 3

   Inspect the hydraulic system for dirt or debris that could cause the Y077 valve actuator to mechanically jam

4. 4

   Check the wiring harness and connector at the Y077 valve for corrosion, damage, or loose pins causing a voltage drop to the solenoid

1. 1

   Warm-Up and Reset

   Start the tractor and allow the hydraulic fluid to reach 40–50°C. Clear the fault code via the tractor's terminal or the FENDIAS diagnostic tool. If the code was triggered by a cold start and does not return, no further repair is needed.

2. 2

   Relieve Pressure

   If the fault persists, safely park the tractor, lower the rear hitch completely, and relieve all hydraulic pressure in the system.

3. 3

   Inspect the Valve

   Locate the Y077 EHR rear cut-off valve on the rear hydraulic control block. Disconnect its electrical connector.

4. 4

   Remove and Clean

   Extract the Y077 valve from the manifold. Inspect the spool and the bore for scoring, mechanical binding, or debris.

5. 5

   Replace if Jammed

   If the valve is mechanically jammed, heavily scored, or if the solenoid fails an electrical resistance test, the valve must be replaced.

6. 6

   Reassembly

   Install the new or cleaned valve, torque to OEM specifications, and reconnect the wiring harness.

7. 7

   Final Testing

   Start the tractor, check for leaks, and use the FENDIAS tool to clear the 08.1.F4 code. Test the rear power lift to ensure the EHR system operates smoothly without locking out.