HYUNDAI

26-01-082H TSB

2026-10-12 · NHTSA 11038467

A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.

Manufacturer summary

Original wording in English

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.

Repeated filings are grouped only when make, bulletin number, publication date and complete summary agree. Original record numbers are retained. Older publications remain available, and an explicit later version is shown when established. Pre-1994 vehicle associations are separated from default results; an unspecified year does not mean all model years apply.