Hyundai bulletin 25-EM-007H
What it saysSome 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… NHTSA’s full summary ↓
Hyundai filed this with NHTSA as a service bulletin dated Dec 18, 2025, received Jan 6, 2026, about the engine — 1 document under this number: 25-EM-007H TSB. It names 11 model years (2020–2025). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationWhat it applies to, as the document itself states it — the build window in the manufacturer’s own words, read by machine from the PDF NHTSA serves. The build date is on the certification label in the driver’s door jamb; the dealer settles a borderline vehicle by its VIN.
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.
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 25-EM-007H TSB | Service bulletin | Dec 18, 2025 | 11027036 | PDF, 813 KB |
What the document itself lists
The manufacturer titles it “ITM THERMOSTAT SPRING INSTALLATION &”.
Parts the bulletin names — the first 40 it lists
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 25689-2J001QQH | Spring | — | eBay Motors → |
| 25623-2J000QQH | — | — | |
| 00232-19098 | Coolant | — | eBay Motors → |
| 39171-2JCB0 | — | — | |
| 39173-2JCB0 | — | — | |
| 39171-2JBE0 | — | — | |
| 39171-2JCC0 | — | — | |
| 39171-2JBB0 | — | — | |
| 39173-2JCC0 | — | — | |
| 39171-2JBC0 | — | — | |
| 39171-2JCB5 | — | — | |
| 39171-2JBD5 | — | — | |
| 39171-2JCC5 | — | — | |
| 39171-2JCB1 | — | — | |
| 39173-2JCB1 | — | — | |
| 39171-2JCC1 | — | — | |
| 39171-2JBB1 | — | — | |
| 39173-2JCC1 | — | — | |
| 39171-2JBC1 | — | — | |
| 39171-2JCB6 | — | — | |
| 39171-2JBD6 | — | — | |
| 39171-2JCC6 | — | — | |
| 39171-2JBB6 | — | — | |
| 39171-2JCD1 | — | — | |
| 39171-2JBG1 | — | — | |
| 39171-2JCE1 | — | — | |
| 39171-2JBF1 | — | — | |
| 39171-2JCC2 | — | — | |
| 39171-2JCB7 | — | — | |
| 39171-2JBD7 | — | — | |
| 39171-2JCC7 | — | — | |
| 39171-2JBB7 | — | — | |
| 39171-2JCD2 | — | — | |
| 39171-2JBG2 | — | — | |
| 39171-2JCE2 | — | — | |
| 39171-2JBF2 | — | — | |
| 39177-2JDF0 | — | — | |
| 39173-2JDF0 | — | — | |
| 39175-2JDF0 | — | — | |
| 39171-2JDF0 | — | — |
Read by machine from the document NHTSA serves (14 pages), read Sep 30, 2026. A part number is shown only where it matches Hyundai’s own catalogue shape, an operation only with its code and time, and a description only where the reader got it whole; anything it could not settle is left out, and the PDF is the record. Times are the manufacturer’s warranty allowances, not a quote. Listings and prices on eBay Motors are the seller’s.
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The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themA vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 11 model years this bulletin names have filed 1,398 complaints with NHTSA since 2015. 294 of them name Engine — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
The knock sensor on the engine fails when exposed to any amount of water. The car is designed in a way that lets on too much. It’s something that is VERY common amongst owners of these vehicles. It’s a safety flaw that needs to be fixed because it puts the car in “limp” mode. That makes the car instantly halt acceleration.
2023 Hyundai Kona · Engine · filed with NHTSA Mar 10, 2024 · ODI 11576498
Initially had loss of cabin heat. Later, vehicle randomly overheated. Repair shop replaced EGR due to finding confidant buildup of water/coolant mix. Within one week, problem returned. Dealer notified me that while replacing another part they found a TSB for coolant leakage into exhaust that was consistent with my issue.
2021 Hyundai Sonata · Engine · filed with NHTSA Feb 13, 2024 · ODI 11571605
While driving on the interstate, the car went into limp mode (does not rev above 2000 rpm). I was unable to maintain speed or merge back into interstate. The dealership has inspected the vehicle, however, they confirm everything is normal. The car did give an engine error code of P132600 for Powertrain.
2022 Hyundai Kona · Engine · filed with NHTSA Sep 3, 2024 · ODI 11612224
In depth: 2021 Hyundai Sonata engine problems →
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the engine
Source: same model, same component group34 other manufacturer communications filed against these Hyundai models under the same component group (engine), newest first. The eight newest are listed; the rest are on the Hyundai list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| 26-EM-016H | Service bulletin | Oct 8, 2026 | Some vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin outlines the… |
| 26-EM-015H | Service bulletin | Oct 7, 2026 | Certain vehicles equipped with internal combustion engines may exhibit higher-than-expected engine oil consumption. This bulletin provides t… |
| 9D1 | Service campaign | Sep 22, 2026 | Certain Kona (OS) vehicles equipped with the 1.6T-GDI engine may exhibit elevated engine-out emissions that may not meet engine-out NOx… |
| 9D3 | Service campaign | Sep 11, 2026 | Certain Elantra (ADA) vehicles may have been incorrectly updated with Cylinder Noise Detection System (CNDS) software that can set DTC P1327… |
| 26-FL-003H | Service bulletin | Jul 1, 2026 | Some Kona (SX2) vehicles equipped with the 1.6L T‑GDI engine may exhibit false “engine left idling” notifications in the MyHyundai app, even… |
| 9C2 | Service campaign | May 21, 2026 | Certain 2019 – 2020 model year Santa Fe, 2017 – 2018 model year Santa Fe Sport, 2015 – 2019 model year Sonata, and 2018 – 2021 model year Tu… |
| 26-EE-003H | Service bulletin | Apr 18, 2026 | Some vehicles may exhibit difficulty starting in cold weather. This bulletin provides the procedure to perform an inspection on the starter… |
| T6G | Warranty extension | Mar 26, 2026 | This TSB references the Op codes to use for claim submission and the Parts required based on the vehicle’s inspection results from TSB 22-01… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Hyundai, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Hyundai 25-EM-007H a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the 25-EM-007H repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every Hyundai warranty extension on file lists the ones Hyundai has filed.
Which vehicles does 25-EM-007H cover?
The manufacturer filed it against 11 model years: 2023 Hyundai Elantra, 2022 Hyundai Elantra, 2021 Hyundai Elantra, 2025 Hyundai Kona, 2024 Hyundai Kona, 2023 Hyundai Kona and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone. The document itself sets the build window: built 12 Sep 2020 – 17 Aug 2023; Elantra (CN7A): built 25 Sep 2020 – 2 Jun 2023; 2022 - 2023 Kona (OS): built 2 Mar 2021 – 17 Aug 2023 — the build date is on the certification label in the driver’s door jamb.