Fendt 0A.1.A1 – Auxiliary Control Units / A002 E-box: EEPROM fault while loading

The EEPROM is failing to load its stored configuration data properly during startup or operation. As a direct safety consequence, the affected auxiliary control valve(s) will move to the neutral position and lock, preventing any hydraulic operation.

• 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 Katana 65 forage harvesters

1. 1

   Cycle Power: Restart the tractor to see if the EEPROM loading error was a temporary glitch.

2. 2

   Check Voltage/Fuses: Verify the power supply to the CAN-Bus and E-box. Check the A013 fuse board, specifically fuses F040 and F041, as voltage drops or weak batteries can cause memory loading and CAN communication errors.

3. 3

   Check for Accompanying Codes: Look for related CAN bus communication faults (e.g., 0A.1.X0) which indicate a specific valve is not reporting to the CAN bus, pointing to a wiring issue rather than a central module failure.

4. 4

   Software Check: Connect the FENDIAS diagnostic tool to see if the module can still be communicated with, preparing for a software re-flash.

1. 1

   Connect diagnostic tool

   Connect the Fendt diagnostic tool (FENDIAS) to the tractor.

2. 2

   Perform EOL programming

   Perform an EOL (End-Of-Line) programming on the A002 E-box / Auxiliary control units to attempt to rewrite the corrupted EEPROM data.

3. 3

   Clear fault codes

   Clear the fault codes and cycle the ignition.

4. 4

   Test auxiliary valves

   Test the auxiliary valves to ensure they no longer lock in the neutral position.

5. 5

   Evaluate EOL programming results

   If the EOL programming fails, or if the fault immediately returns upon startup, the internal EEPROM on the E-box is physically damaged.

6. 6

   Remove E-box

   Remove the A002 E-box / Control Module.

7. 7

   Replace or repair E-box

   Replace the E-box with a new unit, or send the existing unit to a specialized agricultural electronics repair service.

8. 8

   Program new module

   If the module is replaced, perform a full EOL programming and calibration on the new module so it registers the tractor's specific valve configuration.