# Service campaign 25\-01\-063H TSB

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service campaign
- NHTSA id: 11023408
- Published by NHTSA: 2025\-10\-01
- Manufacturer's number: 25\-01\-063H TSB
- Manufacturer's date: 2025\-09\-23
- Campaign id or software version: T9E
- NHTSA component: ENGINE

## NHTSA's summary

Certain IONIQ Electric \(AE EV\) and Kona Electric \(OS EV\) vehicles may exhibit a restricted coolant flow condition, which may be accompanied by a warning message \(e.g., Coolant Supplement, Refill Inverter Coolant\) in the cluster. No related DTCs are stored, and coolant level is normal in the reservoir tank. The coolant flow may be restricted by debris, causing abnormally high Electric Water Pump \(EWP\) speed. This TSB contains instructions for confirming high RPMs in the EWP, then using the Coolant Flushing Equipment Set to flush and clean debris from the various cooling system circuits. The coolant will be replaced with the updated Electric Vehicle Battery System Coolant \(BSC\-2\) low\-conductivity blue coolant.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2025/MC-11023408-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2025/MC-11023408-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Engine

## Vehicles listed

- 2020 to 2021 HYUNDAI IONIQ ELECTRIC
- 2019 to 2022 HYUNDAI KONA ELECTRIC

## Recalls for the same vehicles and component

- [2021252](/recalls/tc/2021252.md), 2021-04-28: Engine
- [21V301000](/recalls/nhtsa/21V301000.md), 2021-04-28: ENGINE

## Other bulletins for the same vehicles and component

- [26\-EM\-016H TSB](/bulletins/11038458.md), 2026-10-14, Service bulletin: ENGINE. Some vehicles equipped with internal combustion engines may exhibit higher\-than\-expected engine oil consumption. This bulletin outlines the combustion chamber cleaning procedure for vehicles diagnosed with this condition. All internal combustion engines consume some engine oil during normal operation, depending on driving conditions and mileage, and this procedure should only be performed when deemed necessary based on inspection and diagnosis of the vehicle as outlined in TSB 26\-EM\-015H, Engine Oil Consumption – Inspection \& Repair Guidelines, or the latest revision.
- [26\-EM\-015H TSB](/bulletins/11038456.md), 2026-10-13, Service bulletin: ENGINE. Certain vehicles equipped with internal combustion engines may exhibit higher\-than\-expected engine oil consumption. This bulletin provides the inspection and repair procedures for vehicles exhibiting this condition. All internal combustion engines consume engine oil as part of normal engine operation. Oil consumption rates may vary based on mileage, operating conditions, driving habits, and maintenance history. Hyundai recommends following the prescribed maintenance schedule and periodically checking the engine oil level using the dipstick to maintain proper engine oil level.
- [9D1 OL](/bulletins/11037496.md), 2026-09-26, Service campaign: ENGINE. Hyundai has become aware that certain Kona vehicles equipped with 1.6T\-GDI engines may not meet engine\-out NOx \(Nitrogen Oxides\) and Particulate Matter \(PM\) emission standards.
- [26\-01\-027H DN](/bulletins/11036623.md), 2026-09-02, Service campaign: ENGINE. Certain Kona \(OS\) vehicles equipped with the 1.6T\-GDI engine may exhibit elevated engine\-out emissions that may not meet engine\-out NOx \(Nitrogen Oxides\) and Particulate Matter \(PM\) emission standards.
- [26\-01\-027H TSB](/bulletins/11036622.md), 2026-09-02, Service campaign: ENGINE. Certain Kona \(OS\) vehicles equipped with the 1.6T\-GDI engine may exhibit elevated engine\-out emissions that may not meet engine\-out NOx \(Nitrogen Oxides\) and Particulate Matter \(PM\) emission standards. This bulletin provides the instructions to update the emission logic within the Engine Control Module \(ECM\) to improve engine\-out NOx and PM emissions within permissible specifications.
- [26\-EE\-003H TSB](/bulletins/11031400.md), 2026-04-21, Service bulletin: ENGINE; ELECTRICAL SYSTEM. Some vehicles may exhibit difficulty starting in cold weather. This bulletin provides the procedure to perform an inspection on the starter magnetic switch for potential freezing and, if necessary, replace the starter magnetic switch \(solenoid\) assembly.
- [25\-EM\-007H TSB](/bulletins/11027036.md), 2026-01-06, Service bulletin: ENGINE. Some Elantra \(CN7, CN7A\), Kona \(OS, SX2\), and Sonata Hybrid \(DN8 HEV\) vehicles equipped with 2.0L engines may illuminate a warning lamp for DTC P218100 \(Cooling System Performance\) related to the Integrated Thermal\-Management Module \(ITM\). Follow the service procedure in this bulletin to install a spring onto the thermostat within the ITM, in order to prevent premature opening, and perform an ECU software update on affected vehicles.
- [24\-EM\-005H](/bulletins/11006840.md), 2024-09-04, Service bulletin: ENGINE. Certain 2022MY Kona \(OS\) vehicles may exhibit a slight radiator coolant leak. Follow the procedure outlined in this bulletin to inspect and if necessary, replace the radiator to correct the condition.
- [24\-FL\-003H](/bulletins/10252354.md), 2024-04-02, Service bulletin: ENGINE AND ENGINE COOLING. This bulletin contains the software update procedure for the Engine Control Unit \(ECU\) on certain 2021\-2023MY Elantra \(CN7\) and 2022\-2023MY Kona \(OS\) vehicles equipped with the 1.6 liter T\-GDI Gamma 2 engine, that may exhibit a warning lamp with one or more of the DTCs listed below: • P250F \- Engine Oil Level Too Low • P011B, P050C \- Engine Coolant Temperature/intake Air Temperature Correlation • P00B7, P2B60 \- Engine Coolant Flow Low/Performance
- [23\-EM\-005H](/bulletins/10247189.md), 2023-12-15, Service bulletin: ENGINE AND ENGINE COOLING. This bulletin provides important checkpoint guidelines when performing engine oil and filter change services.

JSON: [/v1/bulletins/11023408](/v1/bulletins/11023408)

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