26-01-082H TSB

Certain IONIQ 5 (NEA EV) vehicles may experience Malfunction Indicator Lamp (MIL) illumination and false battery overtemperature fault diagnosis caused by water ingress into the high voltage battery system. This condition may cause unnecessary fail-safe activation, potentially resulting in reduced vehicle performance or limited vehicle operation if the vehicle is continually driven. This bulletin provides the service procedure to update the Battery Management System (BMS) software to optimize the fail-safe activation logic to prevent false activation. Additionally, diagnostic criteria for DTC P1AD300 “Hybrid/EV Battery Abnormal Performance: MISD” has also been improved to enhance diagnostic accuracy.