Reference meaning
What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
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A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Scan worksheet →Manufacturer wording
Source wording can vary by vehicle and suffix. It is shown as written, not as a universal diagnosis.
P1AD300Hybrid/EV Battery Abnormal Performance: MISD
Manufacturer communications
2Original wording in English
HYUNDAI
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 …
HYUNDAI
Certain 2025MY IONIQ 5 (NEA EV) vehicles may experience a charging issue where a voltage difference between battery cells prevents the High Voltage Battery from fully charging. The two DTCs associated with this issue are: • P1AA700 – Hybrid/EV Battery Abnormal Performance: Cell Voltage Deviation • P1AD300 – Hybrid/EV Battery Abn…
Check vehicle applicability
3A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.