Error Codes Occur During ECU Upgrade (5021-10-7000, 5021-81-7000)

Symptom:

Error code 5021-10-7000 occurs while performing an ECU upgrade.

✅ Cause

This error may occur in the following situations:

• The applicable control unit (ECU) is not installed in the vehicle.

• No response signal is detected from the control unit due to a control unit malfunction or a similar issue.

🛠️ Resolution

1. If the applicable control unit is not installed in the vehicle

   • The vehicle is not eligible for this upgrade; therefore, the ECU upgrade cannot be performed.

   • First, verify whether the applicable control unit is physically installed in the vehicle.

2. If the error occurs even though the applicable control unit is installed

   • No signal may be detected from the control unit due to a control unit malfunction or communication fault.

   • Use the diagnostic functions for the same vehicle system to verify that the control unit is operating normally.

   • If the same error (5021-10-7000) continues to occur after diagnosis, the control unit may be in an unrecoverable state.

   • In this case, request additional technical support from the manufacturer.