Fendt A.1.5A – A057 - ECU, steering controller (Auto-Guide): Invalid EEPROM parameters for the steering control regulator

The ECU has detected an "invalid data set" within its memory, meaning the software parameters required to operate the automated steering system are corrupted, missing, or unreadable.

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

1. 1

   Verify electrical supply lines to the steering valve block (Y087) and the pilot pressure solenoid valve (Y099) for breaks or shorts, as wiring issues can trigger communication or parameter faults.

2. 2

   Connect the Auto-Guide COM III tool box with the 68-pin adapter box and specific adapter cable to the A057 ECU to read live data and confirm EEPROM corruption.

3. 3

   Check for related codes such as A.1.55 (EEPROM description fault), A.1.56 (EEPROM reading fault), or A.1.57 (EEPROM contains invalid data) that point to the same internal memory failure.

1. 1

   EOL Programming

   Connect the tractor to the FENDIAS diagnostic software. Perform an EOL (End of Line) programming procedure on the A057 Steering Controller ECU to attempt to flash the correct, valid data set back onto the EEPROM.

2. 2

   Recalibrate

   If the EOL programming is accepted, restart the tractor and perform calibration code 2401 (steering angle sensor calibration) to ensure the steering controller is properly synced with the steering hydraulics.

3. 3

   Replace the ECU

   If the EOL programming fails to write to the EEPROM (indicating physical memory failure on the circuit board), the A057 ECU must be entirely replaced and subsequently programmed.