Fendt 9.1.A0 – A002 - ECU, enhanced control: ECU, enhanced control — EEPROM fault while storing.

The internal EEPROM (Electrically Erasable Programmable Read-Only Memory) within the enhanced control unit has failed during a data storage operation. As a result, set values for the enhanced controls (such as spool valve settings, transmission rapid reversing ramp parameters, or linkage settings) are not saved when the tractor is turned off or adjusted.

• 409 Vario
• 410 Vario
• 411 Vario
• 412 Vario
• 711 Vario
• 712 Vario
• 714 Vario
• 715 Vario
• 716 Vario
• 717 Vario
• 718 Vario
• 916 Vario
• 920 Vario
• 924 Vario
• 926 Vario
• 930 Vario
• 411 Vario COM III
• 412 Vario COM III
• 413 Vario COM III
• 414 Vario COM III
• 415 Vario COM III
• 712 Vario COM III
• 714 Vario COM III
• 716 Vario COM III
• 718 Vario COM III
• 818 Vario COM III
• 820 Vario COM III
• Fendt Farmer 400 Vario
• Fendt Favorit 700 Vario
• Fendt Favorit 900 Vario
• Fendt 300 Vario series
• Fendt 400 Vario series
• Fendt 700 Vario series
• Fendt 800 Vario series
• Fendt 900 Vario series

1. 1

   Check voltage supply and ground connections to the A002 ECU, including the CAN-Bus voltage supply on fuse board A013 (specifically fuses F040 and F041), as a voltage drop during a write cycle can cause an EEPROM storing fault.

2. 2

   Check for accompanying CAN bus communication codes (e.g., 0.0.11, 0.0.15, 0.0.16) which might indicate a broader wiring harness or voltage issue rather than an internal ECU failure.

3. 3

   Connect the FENDIAS diagnostic tool and attempt an End-of-Line (EOL) reprogramming or load a new data record to the A002 ECU to determine if it is a software glitch.

1. 1

   Power Down

   Turn off the tractor and disconnect the battery to prevent electrical spikes.

2. 2

   Access the ECU

   Locate the A002 ECU in the cab (usually on the right mudguard). Remove the interior trim panel to expose the electronics box.

3. 3

   Disconnect

   Carefully unplug the main wiring harness connectors (e.g., separation point X031) from the A002 ECU.

4. 4

   Remove and Replace

   Unbolt the defective A002 ECU from its mounting bracket and install the replacement unit.

5. 5

   Reconnect and Reassemble

   Plug the wiring harnesses back in securely and reinstall the cab trim panel.

6. 6

   EOL Programming

   Connect the FENDIAS diagnostic laptop and perform End-of-Line (EOL) programming to pair the ECU with the tractor, calibrate the transmission ranges, and register the hydraulic spool valves.