Fendt 08.1.F7 – A050 ECU (Basic Control Unit): Y077 - EHR cut-off valve, rear: Position pickup sensor error.

When this fault is triggered, the tractor's safety protocols engage: the valve automatically moves to the neutral position and locks, and the hydraulic pilot pressure is turned OFF. This prevents the rear power lift from operating unexpectedly.

• 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)
• 922
• 924
• 927
• 930
• 933
• 936

1. 1

   Test the voltage at the Y077 control pressure solenoid valve (should read 12-14 VDC when active, 0 VDC when inactive)

2. 2

   Inspect the wiring harness and connector at the Y077 valve's position pickup sensor for corrosion, damaged pins, or a faulty signal line

3. 3

   Check the passive bus system to ensure the bus ends are properly sealed off with terminating resistors

4. 4

   Inspect the hydraulic fluid and area for contamination, which can cause the valve actuator to mechanically jam

1. 1

   Preparation

   Ensure the tractor is in a safe initial condition for measurements. The engine should be off (or at idle if live testing is required), valves and EPC locked, and hydraulic pressure released.

2. 2

   Locate the Component

   Locate the Y077 EPC cut-off valve, which is situated at the rear of the tractor on the rear valve block.

3. 3

   Inspect and Clean

   Disconnect the electrical connector to the Y077 valve. Clean the contacts and verify that the position pickup sensor is not physically damaged.

4. 4

   Replace the Valve

   If the electrical supply is verified but the position sensor continues to report an error, the sensor/valve assembly has failed. Remove the hydraulic lines (caution: catch any leaking hydraulic fluid) and unbolt the Y077 valve. Install the new OEM cut-off valve.

5. 5

   Reassembly and Calibration

   Reconnect the hydraulic lines and electrical harness. Clear the fault codes using the FENDIAS diagnostic tool or the tractor's onboard terminal. Test the rear power lift to ensure the valve no longer defaults to neutral and locks.