Error code occurred during ECU upgrade (5021-81-7000)

Symptoms

Possible Causes

• ECU installation issue: Incorrect physical installation may cause unstable communication.
• ECU condition issue: The ECU may be in an unstable state, preventing proper communication.

Solution

1. Check physical installation – Ensure the ECU is properly installed.
2. Restart the ECU – Turn off the power to the ECU and restart it before retrying the upgrade.
3. IBU-BCM power reset – If the issue is related to the BCM, turn off the power and retry after 2 hours.

Additional Support

If the issue persists after following the steps above, please contact one of following numbers for assistance. If necessary, we can provide a file set with an extended ECU response timeout to retry the upgrade. However, note that depending on the ECU condition, the upgrade may still fail.

USA
KIA 888-542-4371
HYUNDAI 888-437-0308
GENESIS 833-681-3926

CANADA
KIA 888-641-4244
HYUNDAI 888-641-4243