Error Code [5021-31-7F22] Occurs During KDS 2.0 ECU Upgrade

Symptom:  Error code [5021-31-7F22] occurs during an ECU upgrade.

Cause:

1. The control unit returns a negative response to the ECU upgrade erase memory or checkdependency command.
2. This error usually appears when the software being installed does not match the control unit specifications.

Solution: 

1. Confirm whether the ECU upgrade was performed in Auto Mode or Manual Mode.
2. If the upgrade was performed in Manual Mode, confirm that the ECU upgrade was attempted using the correct subcategory for the control unit.
3. Check whether any aftermarket equipment is installed in the vehicle.
4. Confirm that all upgrade conditions are met. For example, the upgrade must be performed with IG On, and the 12 V battery state of charge must be checked.

If the issue persists, contact the control unit manufacturer or the Kia Research and Development Centre.