ECU 000629.12 – ECU EEPROM Error at Startup. John Deere System Advisory.

ECU 000629.12 (ECU 629.12)

Code: 000629.12

Shortcode: 629.12


Error code ECU 000629.12 indicates an internal ECU fault related to EEPROM, specifically occurring during the software launch phase. This problem suggests potential data corruption or hardware malfunctions within the ECU.


The ECU may not function correctly, impacting its ability to control various engine and vehicle functions.


  • ECU Diagnostic Evaluation: Perform a detailed diagnostic to determine the extent of EEPROM or related hardware issues.
  • Correct Software or Hardware Issues: Address any software corruption or hardware malfunctions, possibly requiring ECU repair or replacement.
  • Ensure Software Integrity: Reinstall or update ECU software to ensure all operational instructions are correctly stored and executed.
  • Comprehensive Functionality Testing: After addressing the issues, test the ECU thoroughly to ensure all systems are operational.


EEPROM faults can significantly disrupt ECU functionality. Prompt and thorough resolution is necessary to maintain vehicle integrity and safety.

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