Fendt 1.1.06 – A002 - ECU, enhanced control: EST memory could not be reserved

The Tractor Management System (TMS) is switching off and becomes non-operable. This means the tractor will lose automated engine/transmission management functions and may be restricted to emergency or manual operating modes.

• 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 300 Vario (COM III)
• Fendt 400 Vario (COM III)
• Fendt 700 Vario (COM III)
• Fendt 800 Vario (COM III)
• Fendt 900 Vario (COM III)

1. 1

   Check Power Supply: Verify the voltage supply to the CAN-Bus and the A002 ECU. Check the main fuse board (A013), specifically looking for blown fuses that supply the enhanced control bus.

2. 2

   Check CAN Bus Wiring: Inspect the wiring harness and connectors between the A002 ECU, the EST (diagnostic/programming interface), and the side console. Look for corrosion, loose pins, or short circuits to ground.

3. 3

   Scan for Associated Codes: Check if other CAN communication faults are present (e.g., 1.1.04 Checksum error, or 1.1.9E CAN connection fault). If multiple modules are failing to communicate, the issue is likely a physical CAN bus wiring fault rather than an internal memory failure of the A002 ECU.

1. 1

   Connect diagnostic interface

   Connect the FENDIAS diagnostic interface to the tractor's diagnostic port.

2. 2

   Establish communication

   Establish communication with the A002 Enhanced Control ECU.

3. 3

   Execute EOL programming

   Execute the EOL programming procedure to re-flash the module and re-initialize the memory parameters.

4. 4

   Verify TMS initialization

   Clear the fault codes and cycle the ignition to verify if the TMS system initializes correctly.

5. 5

   Replace A002 ECU

   If the EOL programming fails to reserve memory or the EPROM is physically corrupted, the A002 ECU (E-box) must be replaced or sent to a specialized agricultural electronics repair facility.

6. 6

   Perform post-repair calibration

   If the A002 ECU is replaced or heavily reprogrammed, you must perform a full calibration sequence for all connected sensors (including the clutch pedal, suspension position sensors, and transmission sensors) using their respective calibration codes (e.g., code 4005 for the foot throttle, code 7666 for suspension).