Hyundai bulletin 26-EM-009H
What it saysSome Sonata (DN8) and Tucson (NX4/NX4A/NX4M) vehicles equipped with the 2.5L Theta III GDI engine may display a warning lamp and store Diagnostic Trouble Code (DTC) P2B59F0, which relates to the Integrated Thermal… NHTSA’s full summary ↓
Hyundai filed this with NHTSA as a service bulletin dated Mar 24, 2026, received Mar 30, 2026, about the electrical system — 1 document under this number: 26-EM-009H TSB. It names 4 model years (2024–2025). 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 Sonata (DN8) and Tucson (NX4/NX4A/NX4M) vehicles equipped with the 2.5L Theta III GDI engine may display a warning lamp and store Diagnostic Trouble Code (DTC) P2B59F0, which relates to the Integrated Thermal Management Module (ITM) circuit due to a logic error. This bulletin provides instructions to update the Engine Control Module (ECM) logic to correct this condition.
Trouble codes it names: P2B59 all 1 read from the document itself; NHTSA’s summary names none
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 26-EM-009H TSB | Service bulletin | Mar 24, 2026 | 11030329 | PDF, 435 KB |
What the document itself lists
The manufacturer titles it “ECM SOFTWARE UPDATE FOR ITM LOGIC IMPROVEMENT –”.
Parts the bulletin names
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 39110-2S356 | — | — | |
| 39110-2S357 | — | — | |
| 39110-2S358 | — | — | |
| 39110-2S361 | — | — | |
| 39104-2S403 | — | — | |
| 39104-2S404 | — | — | |
| 39104-2S405 | — | — | |
| 39104-2S457 | Tucson | — | eBay Motors → |
| 39110-2S364 | — | — | |
| 39110-2S365 | — | — | |
| 39110-2S367 | — | — | |
| 39110-2S369 | — | — | |
| 39110-2S370 | — | — | |
| 39110-2S371 | — | — | |
| 39104-2S436 | — | — | |
| 39104-2S437 | — | — | |
| 39104-2S438 | — | — | |
| 39104-2S459 | Tucson | — | eBay Motors → |
| 39104-2S440 | — | — | |
| 39104-2S441 | — | — | |
| 39104-2S442 | ECM SOFTWARE UPDATE FOR ITM LOGIC IMPROVEMENT – DTC P2B59F | — | eBay Motors → |
| 39104-2S205 | — | — | |
| 39104-2S206 | — | — | |
| 39104-2S207 | — | — | |
| 39104-2S241 | — | — | |
| 39104-2S242 | — | — | |
| 39104-2S243 | — | — | |
| 39103-2S202 | — | — |
Read by machine from the document NHTSA serves (9 pages), read Sep 29, 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 4 model years this bulletin names have filed 689 complaints with NHTSA since 2015. 192 of them name Electrical System, 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.
On the 2025 Hyundai Tucson, the 15 owners who gave an odometer reading for Electrical System reported it at a median of 5,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
On Feb. 10, 2026, my Sonata began showing a blue screen on the infotainment screen when the vehicle was in reverse. The blue screen contained the message "Incoming Camera Signal Error. Please try again later." Between Feb. 10 and 22, I continued seeing the aforementioned blue screen and message.
2025 Hyundai Sonata · Electrical System · filed with NHTSA Jun 24, 2026 · ODI 11746271
The contact owns a 2024 Hyundai Tucson. The contact stated that while the vehicle was parked, while attempting to enter the vehicle, the key fob failed to function as intended. The contact was unable to unlock the doors to the vehicle. The contact noticed that the battery was completely drained.
2024 Hyundai Tucson · Electrical System · filed with NHTSA Sep 10, 2025 · ODI 11686438
📌 NHTSA Complaint Description (Modify as Needed) 🚨 Safety Issue: I purchased a brand-new 2025 Hyundai Tucson Hybrid on March 3, 2025, and within 5 minutes of driving and less than 20 miles, the vehicle stalled three times on a busy highway without warning.
2025 Hyundai Tucson · Engine · filed with NHTSA Mar 12, 2025 · ODI 11648012
In depth: 2025 Hyundai Tucson electrical 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 electrical system
Source: same model, same component group61 other manufacturer communications filed against these Hyundai models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Hyundai list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| P38 | Service bulletin | Oct 29, 2026 | Certain Tucson (NX4, NX4A), Tucson Hybrid (NX4 HEV), and Tucson Plug-in Hybrid (NX4 PHEV) vehicles may be eligible for the installation of t… |
| 26-GI-003H | Service bulletin | Oct 27, 2026 | This bulletin provides information related to the navigation and head unit software changes introduced in the 2026 2nd Navigation Map and So… |
| 26-EM-014H | Service bulletin | Sep 16, 2026 | Some Tucson (TL) vehicles equipped with a 2.0L engine may exhibit a continued DTC P132600 after an ECM logic update has been performed per T… |
| 26-BE-025H | Service bulletin | Aug 21, 2026 | Some Tucson (NX4, NX4A, NX4M), Tucson Hybrid (NX4 HEV), and Tucson Plug-In Hybrid (NX4 PHEV) vehicles may exhibit a 12-volt battery drain du… |
| LA29 / LA30 | Warranty extension | Jul 14, 2026 | Certain 2024-2026MY Sonata (DN8) and 2024-2026MY Sonata Hybrid (DN8 HEV) vehicles may exhibit intermittent battery discharge condition due t… |
| LA30 | Warranty extension | Jul 13, 2026 | Certain Sonata Hybrid (DN8 HEV) vehicles may exhibit intermittent battery discharge conditions due to the air conditioning controller not fu… |
| LA29 | Warranty extension | Jul 13, 2026 | Certain Sonata (DN8) vehicles may exhibit intermittent battery discharge condition due to the air conditioning controller not fully powering… |
| 26-EE-007H | Service bulletin | Jun 17, 2026 | Some Palisade (LX2), Tucson (NX4), and Tucson Hybrid (NX4 HEV) vehicles may experience battery drain due to continuous operation of the cool… |
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 26-EM-009H 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 26-EM-009H 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 26-EM-009H cover?
The manufacturer filed it against 4 model years: 2025 Hyundai Sonata, 2024 Hyundai Sonata, 2025 Hyundai Tucson, 2024 Hyundai Tucson. 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 18 Oct 2023 – 2 Jun 2025; Tucson (NX4): built 27 Jan 2024 – 5 Sep 2024; Tucson (NX4A): built 22 Jun 2023 – 20 Feb 2025 — the build date is on the certification label in the driver’s door jamb.