Fendt 08.1.A0 – A050 ECU, basic control unit / A024 ECU, EPC B: EEPROM error when saving / Checksum incorrect EOL programming

The control unit is failing to properly save, write, or validate the configuration/calibration data for the rear electronic power lift control (EHR/EPC) valve into its memory. As a safety consequence, the valve typically moves to neutral, locks, and will not respond to programmed automatic modes.

• 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 200 Vario series (V/F/P models)
• Fendt 300 Vario series (including COM III)
• Fendt 400 Vario series (including Farmer 400 and COM III)
• Fendt 700 Vario series (including Favorit 700 and COM III)
• Fendt 800 Vario series (including COM III)
• Fendt 900 Vario series (including Favorit 900 and COM III models 916 through 936)

1. 1

   Attempt to clear the fault code from the instrument panel or via the FENDIAS diagnostic software and check if it returns immediately.

2. 2

   Check the voltage at the Y077 rear EPC cut-off valve using a multimeter (should be approximately 14 VDC when active, 0 VDC when inactive).

3. 3

   Inspect the wiring harness and connectors between the Y077 valve and the A050 or A024 ECU for shorts, corrosion, or breaks.

4. 4

   Verify if the tractor recently had a software update, battery failure, or module replacement that would require End of Line (EOL) reprogramming.

1. 1

   Secure the Tractor

   Park the tractor on a level surface, lower the rear power lift completely (if possible), and turn off the ignition.

2. 2

   Inspect the Y077 Valve

   Locate the Y077 EHR cut-off valve on the rear hydraulic valve block. Check the solenoid actuator to ensure it is not mechanically jammed due to oil contamination, which can sometimes cause the valve to lock and throw electrical faults.

3. 3

   Perform EOL Programming

   Connect the FENDIAS diagnostic tool. Navigate to the A050 basic control unit (or A024) and perform an EOL (End of Line) reprogramming and calibration for the rear EPC.

4. 4

   Replace the ECU (if memory is corrupted)

   If the FENDIAS tool repeatedly fails to write to the ECU and the 'EEPROM error when saving' persists, the internal memory of the A050 basic control unit has failed. The A050 ECU will need to be replaced and programmed to the tractor.

5. 5

   Replace the Valve (if electrically shorted)

   If the Y077 valve solenoid is found to be shorted (causing the ECU to protect itself and drop the save state), replace the Y077 cut-off valve.