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Service bulletin 25-EM-007H 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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11027036
Published by NHTSA2026-01-06
Manufacturer's number25-EM-007H TSB
Manufacturer's date2025-12-18
NHTSA componentENGINE

NHTSA's summary

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.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Trouble codes named

P2181

Vehicles listed
HYUNDAI ELANTRA2021, 2022, 2023
HYUNDAI KONA2022, 2023, 2024, 2025
HYUNDAI SONATA HYBRID2020, 2021, 2022, 2023 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
24V3080002024-05-01. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:GAS RECIRCULATION VALVE (EGR VALVE)
20242552024-04-30. Engine

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
26-EM-016H TSB2026-10-14. Service bulletin. 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 TSB2026-10-13. Service bulletin. 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.
26-FL-003H TSB2026-07-08. Service bulletin. Some Kona (SX2) vehicles equipped with the 1.6L T‑GDI engine may exhibit false “engine left idling” notifications in the MyHyundai app, even when the engine is not running, due to a logic error associated with the front oxygen (O₂) sensor. This condition may also illuminate the Malfunction Indicator Lamp (MIL) and set DTC P223700 (O₂ Sensor Pumping Current Circuit/Open [Bank 1 Sensor 1]). This bulletin provides instructions to perform an ECU software update to correct the O₂ sensor logic and resolve the condition.
26-EE-003H TSB2026-04-21. Service bulletin. 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.
26-EM-003H TSB2026-02-10. Service bulletin. Some Sonata (DN8, DN8A) vehicles may have DTCs P218100, P2181F0, and/or P2181F1 (Cooling System Performance) set in the Engine Control Module, resulting in an illuminated Check Engine warning lamp. Follow the procedure in this TSB to replace the Integrated Thermal Management (ITM) module and update both the Engine Control Module (ECM) and Transmission Control Module (TCM) if applicable. Follow the flowchart in this TSB to update the appropriate modules.
25-01-063H TSB2025-10-01. Service campaign. 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.
25-EE-002H2025-05-02. Service bulletin. Certain Sonata (DN8) and Sonata (DN8A) vehicles may experience issues with the air conditioning due to damaged wiring in the engine room junction box. This bulletin provides instructions to replace the multi-fuse, reroute the damaged wiring using the blower wiring kit, and replace the fuse label.
24-EM-005H2024-09-04. Service bulletin. 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-EM-001H2024-08-07. Service bulletin. Certain 20-22MY Sonata (DN8a), 21-23MY Santa Fe (TMa), and 22-23MY Tucson (NX4a) vehicles may experience a warning lamp illumination for a diagnostic trouble code P2181 that is related to the Integrated Thermal Management Module (ITM). Follow the service procedure outlined in this bulletin to replace the ITM.
24-FL-003H2024-04-02. Service bulletin. 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