Hyundai bulletin 23-FL-004H
What it saysCertain 2015-2019MY Sonata (LFA) vehicles may intermittently exhibit reduced engine power, a “Crank/No Start” condition, and/or have DTC P1233 stored in the ECM due to an internally leaking fuel pump filter housing. NHTSA’s full summary ↓
Hyundai filed this with NHTSA as a service bulletin dated Jun 29, 2023, received Jul 1, 2023, about the engine — 2 documents under this number. It names 4 model years (2016–2019). 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 communicationPicked out of NHTSA’s summary below, word for word. The document itself is the record, and the dealer checks the VIN.
What 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.
Certain 2015-2019MY Sonata (LFA) vehicles may intermittently exhibit reduced engine power, a “Crank/No Start” condition, and/or have DTC P1233 stored in the ECM due to an internally leaking fuel pump filter housing. Hyundai is extending warranty coverage for fuel pump filter assembly repair or replacement to 15 years / 150,000 miles from the date of original retail delivery or date of first use (whichever occurs first) and is valid for original and subsequent owners. Follow the service procedure to inspect the low-pressure fuel pump operation and replace the fuel filter if necessary.
Trouble codes it names: P1233
One of the 357 warranty extensions and special-coverage programs on file — every make, with the term each runs to.
Documents filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| 23-FL-004H | Service bulletin | Jun 29, 2023 | 10238402 | PDF, 409 KB |
| 23-FL-004H | Service bulletin | Jun 29, 2023 | 10238401 | PDF, 378 KB |
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.
Doing the repair yourself, or pricing it before the shop does? Search the part by fitment on eBay Motors — the listing and the price are the seller’s.
Find the engine control module (ecu/ecm) for the 2019 Sonata →Affiliate disclosure: some links on this page are affiliate links. If you request a quote or buy through them we may earn a commission at no extra cost to you. Nothing on this page changes because of it.
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 2,312 complaints with NHTSA since 2015. 1,357 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.
On the 2016 Hyundai Sonata, the 192 owners who gave an odometer reading for Engine reported it at a median of 78,000 miles. That figure is one model year’s, not the whole range this bulletin covers — medians from different model years are not averaged.
The contact owns a 2016 Hyundai Sonata Plug-In Hybrid. The contact stated that on three separate occasions while driving approximately 65 MPH, the “Check Hybrid System - Turn Off Engine” message was displayed. The check engine warning light illuminated. The contact then stated that the vehicle decelerated and went into LIMP Mode.
2016 Hyundai Sonata · Engine · filed with NHTSA Jun 27, 2023
Same problem with this 2018 Hyundai Sonata Limited Hybrid engine as the already recalled 2017 Sonata’s with the same 4 liter/direct fuel injection engines. At approximately 69,000 miles the problems and check engine light analyzed was done by Auto Zone and Brandon Hyundai (3 times each and finding additional problems each time).
2018 Hyundai Sonata · Engine · filed with NHTSA Apr 30, 2022
The primary failure is in the Engine/Powertrain system and Knock Sensor Detection System (KSDS), causing 6 identical sudden engine stalls (OBD-II code P1326) from 09/2000 to 06/2026. Additionally, severe excessive oil consumption was documented during 2 of these diagnostic visits, showing deep-seated engine issues.
2019 Hyundai Sonata · Engine · filed with NHTSA Jul 15, 2026
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 group15 other manufacturer communications filed against the Hyundai Sonata 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 |
|---|---|---|---|
| 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… |
| 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… |
| T6G TXXM | 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… |
| 26-EM-009H | Service bulletin | Mar 24, 2026 | 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 Diagn… |
| 26-EM-003H | Service bulletin | Feb 5, 2026 | Some Sonata (DN8, DN8A) vehicles may have DTCs P218100, P2181F0, and/or P2181F1 (Cooling System Performance) set in the Engine Control Modul… |
| 25-EM-007H | Service bulletin | Dec 18, 2025 | Some Elantra (CN7, CN7A), Kona (OS, SX2), and Sonata Hybrid (DN8 HEV) vehicles equipped with 2.0L engines may illuminate a warning lamp for… |
| 9B3 | Service campaign | Mar 13, 2025 | The exhaust gas recirculation (EGR) valve assembly in certain vehicles may contain a sensor that was contaminated with solder flux during ma… |
| SERVICE CAMPAIGN 9B3 | Service campaign | Sep 25, 2024 | The exhaust gas recirculation (EGR) valve assembly in certain vehicles may contain a sensor that was contaminated with solder flux during ma… |
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 23-FL-004H 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 23-FL-004H 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.
Which vehicles does 23-FL-004H cover?
The manufacturer filed it against 4 model years: 2019 Hyundai Sonata, 2018 Hyundai Sonata, 2017 Hyundai Sonata, 2016 Hyundai Sonata. 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: 2015-2019 Sonata (LFA): built 1 May 2014 – 30 Sep 2019 — the build date is on the certification label in the driver’s door jamb.