EPC 000628.02 – Control Unit Internal Fault

EPC 000628.02 (EPC 628.02)

Code: 000628.02

Shortcode: 628.02


This error code, EPC 000628.02, indicates that the control unit has detected an internal problem during the initialization process (control unit boot sequence after the ignition is switched ON). This suggests that there may be an issue within the control unit itself, potentially affecting its ability to function correctly.


When this error is detected, the control unit may not initialize properly, leading to potential malfunctions in various systems that rely on the control unit. This can result in degraded performance or even a complete failure of certain functions.


Power Cycle the System:

  • Turn off the ignition and restart the system to see if the issue resolves itself upon reinitialization.

Check Control Unit Connections:

  • Inspect the electrical connections to the control unit for any signs of damage, loose connections, or corrosion. Ensure all connections are secure and clean.

Update Control Unit Software:

  • Ensure the control unit is running the latest software version. Update the software if necessary to address potential internal faults.

Perform Diagnostic Tests:

  • Use diagnostic tools to perform a thorough check of the control unit. Look for any specific error codes or issues that may indicate the cause of the internal fault.

Replace Control Unit:

  • If the internal fault persists and cannot be resolved through the above steps, consider replacing the control unit with a new one.


Regular updates and maintenance of the control unit, including ensuring secure connections and up-to-date software, are essential to prevent internal faults and maintain optimal functionality.

Control Units: John Deere

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