Error code occurred during ECU upgrade (5021-27-7F11 on CN7 HEV)

Symptoms

The 5021-27-7F11 error code occurs when an error happens during the ECU upgrade process, and the same ECU upgrade is attempted again.

Applicable ECU Upgrades : 1025.CN7 HEV WARNING LIGHTS AND SLOW ACCELERATION IMPROVING UPGRADE

Cause

This error occurs when the ECU software reprogramming process fails to complete successfully. Under certain conditions or environments, the initial ECU upgrade may fail, and a recovery ECU upgrade attempt may trigger this error code.

Solution

If the 5021-27-7F11 error code appears, the affected ECU must be replaced. Please contact Techline and get a confirmation to replace the ECU.

Customer Support

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

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