Fendt 08.1.A1 – A050 ECU: EEPROM error when reading - Y077 EHR cut-off valve, rear

The control unit is unable to successfully read the EEPROM memory data associated with the rear EHR cut-off valve. As a safety measure, the valve automatically moves to neutral and locks, and the pilot pressure is turned OFF. The rear power lift will be inoperable.

• 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) / Farmer 400
• Fendt 700 Vario (COM III) / Favorit 700
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III) / Favorit 900

1. 1

   Check for related codes such as 08.1.A0 (EEPROM error when saving) or 08.1.A2 (EEPROM error on the valve itself).

2. 2

   Inspect the wiring harness between the A050 Basic Control Unit and the Y077 rear EHR cut-off valve. Look for chafed wires, corrosion, or loose pins at the connectors that could interrupt the data signal.

3. 3

   Verify that the valve is receiving proper voltage. Undervoltage (< 8V) or overvoltage can cause communication dropouts and trigger related 08.1.F-series codes.

4. 4

   Connect the FENDIAS diagnostic software to see if the A050 ECU requires EOL (End-of-Line) programming or if the valve has simply lost its calibration.

1. 1

   Relieve Hydraulic Pressure

   Before servicing any hydraulic components, turn off the tractor and relieve all hydraulic pressure in the system to prevent injury.

2. 2

   Clean the Area

   Thoroughly clean the area around the rear hydraulic valve block to prevent dirt from entering the hydraulic system during removal.

3. 3

   Disconnect Electrical Connections

   Unplug the electrical connector from the Y077 EHR cut-off valve module.

4. 4

   Remove the Valve

   Disconnect the hydraulic lines attached to the rear power lift control valve. Unbolt the valve assembly from the hydraulic block.

5. 5

   Install the New Valve

   Mount the replacement Bosch Rexroth EHR valve, ensuring all O-rings and seals are properly seated. Torque the mounting bolts to OEM specifications.

6. 6

   Reconnect and Bleed

   Reconnect the hydraulic lines and the electrical harness. Top off the hydraulic fluid if necessary.

7. 7

   EOL Programming & Calibration

   A newly installed EHR valve must be registered with the tractor's CAN bus. Use the FENDIAS diagnostic tool to perform EOL programming and run the calibration procedure for the rear power lift (Calibration code '8002' is often required for rear power lift position calibration).

8. 8

   Clear Codes

   Clear the fault memory in the A050 ECU and test the rear hitch functionality.