Honda bulletin A26-003
What it saysUnder certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, and/or misfire. NHTSA’s full summary ↓
Honda filed this with NHTSA as a service bulletin dated Sep 25, 2026, received Aug 24, 2026, about the engine — 2 documents under this number. It names 5 model years (2018–2022). 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 communicationService Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, and/or misfire. In some cases, DTCs P0300 through P0304 may also be stored (DTCs are not required for repair).
Trouble codes it names: P0300 P0304
One of the 432 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 |
|---|---|---|---|---|
| A26-003 | Service bulletin | Sep 25, 2026 | 11037687 | PDF, 4,762 KB |
| A26-003 | Service bulletin | Aug 26, 2026 | 11036336 | PDF, 4,958 KB |
What the document itself lists
The manufacturer titles it “Warranty Extension: 2018–22 Accord (CVT) Cylinder Head Gasket”.
Parts the bulletin names — the first 40 it lists
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 12251-6A0-A11 | GASKET, CYLINDER HEAD (NIPPON LEAKLESS) | 1 | eBay Motors → |
| 12341-59B-013 | GASKET, HEAD COVER | 1 | eBay Motors → |
| 15400-RTA-003 | FILTER, OIL | 1 | eBay Motors → |
| 15533-59B-003 | FILTER ASSY., TURBOCHARGER OILFEED | 1 | eBay Motors → |
| 15535-6A0-A00 | WASHER, SEALING (TURBO FEED LINE) | 1 | |
| 15832-RAA-A01 | OIL SEAL, CONTROL VALVE | 1 | eBay Motors → |
| 16012-5PA-315 | PIPE SET, FUEL JOINT (MSDS) | 1 | eBay Motors → |
| 17105-5AA-004 | GASKET, IN. MANIFOLD | 4 | eBay Motors → |
| 17152-6A0-A00 | TUBE SET, BREATHER (2021-2022) | 1 | eBay Motors → |
| 17275-6A0-A01 | GASKET, TURBOCHARGER IN. JOINTPIPE (D58) | 1 | eBay Motors → |
| 18233-6A0-004 | GASKET A, TURBOCHARGER | 1 | eBay Motors → |
| 18234-59B-004 | GASKET B, TURBOCHARGER | 1 | eBay Motors → |
| 18302-SP0-003 | GASKET, PRE CHAMBER | 1 | eBay Motors → |
| 19012-671-300 | GASKET, DRAIN (DENSO) | 1 | eBay Motors → |
| 19321-59B-004 | GASKET, THERMOSTAT CASE | 1 | eBay Motors → |
| 90012-59B-004 | NUT, SELF-LOCK (10MM) (CATALYST) | 4 | eBay Motors → |
| 90162-T0A-A00 | BOLT, FLANGE (12X40) (SIDE MOUNT BOLT) | 2 | eBay Motors → |
| 90164-T1G-E00 | BOLT, FLANGE (14X68) (SIDE MOUNT BOLT) | 2 | eBay Motors → |
| 90165-TVA-A02 | BOLT-WASHER (12X100) (SIDE MOUNT BOLT) | 1 | eBay Motors → |
| 90172-TVA-A02 | BOLT-WASHER (12X110) (SIDE MOUNT BOLT) | 1 | eBay Motors → |
| 90212-SA5-003 | NUT, SELF-LOCK (10MM) (EXHAUST) | 3 | eBay Motors → |
| 90371-SJD-003 | NUT, FLANGE (14MM) (SIDE MOUNT) (SIDE MOUNT BOLT) | 1 | eBay Motors → |
| 91212-59B-003 | OIL SEAL (43X58X7) (CRANK SEAL) | 1 | eBay Motors → |
| 91311-5A2-A01 | HPFP O-RING | 1 | eBay Motors → |
| 91314-PH7-003 | O-RING | 2 | eBay Motors → |
| 10003-6A0-A00 | GENERAL ASSY., CYLINDER HEAD | 1 | eBay Motors → |
| 15815-6A0-A01 | FILTER ASSY., SPOOL VALVE | 1 | eBay Motors → |
| 16451-5R1-J01 | CLIP, INJECTOR | 4 | eBay Motors → |
| 16453-5R1-J00 | SEAL SET, INJECTOR | 1 | eBay Motors → |
| 19310-6A0-A01 | COVER ASSY., THERMOSTAT | 1 | eBay Motors → |
| 10002-6A0-A02 | GENERAL ASSY., CYLINDER BLOCK | 1 | eBay Motors → |
| 19411-5AA-A01 | O-RING, WATER PASSAGE (OIL) | 1 | eBay Motors → |
| 90002-S10-000 | NUT, FLANGE (10MM) (SWAY BAR LINK) | 1 | eBay Motors → |
| 90163-TVA-A01 | BOLT-WASHER (12X45) (LOWER TORQUE MOUNT BOLT) | 2 | eBay Motors → |
| 90163-TVA-A02 | BOLT-WASHER (12X50) (TRANSMMISSION MOUNT BOLT) | 2 | eBay Motors → |
| 90164-TVA-A02 | BOLT-WASHER (12X105) (LOWER TORQUE MOUNT BOLT) | 2 | eBay Motors → |
| 90166-TVA-A01 | BOLT-WASHER (12X105) (LOWER TORQUE MOUNT BOLT) | 1 | eBay Motors → |
| 90166-TVA-A02 | — | 1 | |
| 90305-S3V-A11 | NUT, SPINDLE | 1 | eBay Motors → |
| 90370-SJA-000 | NUT, SELF-LOCK (12MM) (KNUCKLE) (CLINCH) | 3 | eBay Motors → |
Read by machine from the document NHTSA serves (22 pages), read Oct 4, 2026. A part number is shown only where it matches Honda’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 5 model years this bulletin names have filed 3,826 complaints with NHTSA since 2015. 1,008 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 2018 Honda Accord, the 123 owners who gave an odometer reading for Engine reported it at a median of 70,000 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 2019 Honda Accord. The contact stated while driving approximately 40 MPH, the vehicle inadvertently stalled. The contact stated that the check engine warning light was illuminated. The contact was able to restart the vehicle after waiting approximately two hours. The vehicle was not taken to a local dealer.
2019 Honda Accord · Engine · filed with NHTSA Dec 9, 2021 · ODI 11443227
My car is a hybrid. At times, a Very loud humming noise is produced, due to glitch in software with the ANC. Noise starts and stops suddenly, intermittently, without warning, and is a safety hazard. Noise can build to be extremely loud and jarring, and can last for several minutes.
2020 Honda Accord · Engine · filed with NHTSA Mar 19, 2022 · ODI 11457388
Twice while driving at highway speeds the check engine light came on. My car's engine was misfiring, and I have no acceleration. Both times, I took local roads home on which I could drive below 35 mph. Pulling out from traffic lights and stop signs was difficult.
2021 Honda Accord · Engine · filed with NHTSA Dec 5, 2024 · ODI 11629132
In depth: 2021 Honda Accord engine problems → · 2020 Honda Accord engine problems → · 2019 Honda Accord engine problems → · 2018 Honda Accord 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 group40 other manufacturer communications filed against the Honda Accord under the same component group (engine), newest first. The eight newest are listed; the rest are on the Honda list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| A26-007 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-006 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-005 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| A26-004 | Service bulletin | Sep 25, 2026 | Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience ov… |
| AEBM08262026901 | Other | Aug 26, 2026 | Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience over… |
| A25-017 | Service bulletin | Jun 23, 2026 | Service Bulletin - A slight engine vibration and the Malfunction Indicator Lamp (MIL) is ON with DTC P0700… |
| ATI&03032026905 | Other | Mar 3, 2026 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2023-2025 FHEV Accords & CR-Vs with a customer complaint of a… |
| ATI&10012025906 | Other | Oct 2, 2025 | Dealer Message - American Honda Motor Co., Inc. (AHM) is searching for certain 2023-2024 FHEV Accords & CR-Vs with a customer complaint of a… |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Honda, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Honda A26-003 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 A26-003 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 Honda warranty extension on file lists the ones Honda has filed.
Which vehicles does A26-003 cover?
The manufacturer filed it against 5 model years: 2022 Honda Accord, 2021 Honda Accord, 2020 Honda Accord, 2019 Honda Accord, 2018 Honda Accord. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.