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

Symptom:

Error code 5021-10-7000 occurs during an ECU upgrade.

✅ Cause

This error may occur under the following conditions:

• The applicable ECU is not installed in the vehicle.

• No response signal is detected from the ECU due to an ECU fault or a similar issue.

🛠️ Solution

1. If the applicable ECU is not installed in the vehicle

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

   • First, verify whether the applicable ECU is actually installed in the vehicle.

2. If the error occurs even though the applicable ECU is installed

   • No signal may be detected from the ECU due to an ECU fault or communication failure.

   • Use the diagnostic functions for the same vehicle system to verify that the ECU is operating correctly.

   • If the same error (5021-10-7000) recurs after diagnosis, the ECU may be unrecoverable.

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