Acura bulletin B26-001
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 ↓
Acura filed this with NHTSA as a service bulletin dated Sep 25, 2026, received Aug 27, 2026, about the engine — 2 documents under this number. It names 2 model years (2025–2026). 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 |
|---|---|---|---|---|
| B26-001 | Service bulletin | Sep 25, 2026 | 11037716 | PDF, 4,884 KB |
| B26-001 | Service bulletin | Aug 26, 2026 | 11036421 | PDF, 5,087 KB |
What the document itself lists
The manufacturer titles it “Warranty Extension: 2025–26 ADX Cylinder Head Gasket”.
Parts the bulletin names — the first 40 it lists
| Part number | Description | Qty | Find it |
|---|---|---|---|
| 12251-6A0-A11 | GASKET, CYLINDER HEAD | 1 | eBay Motors → |
| 12341-6VJ-A01 | 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 → |
| 16012-6NA-305 | PIPE SET, FUEL JOINT | 1 | eBay Motors → |
| 17105-5AA-004 | GASKET, IN. MANIFOLD | 4 | eBay Motors → |
| 17275-6A0-A01 | GASKET, TURBOCHARGER IN. JOINTPIPE | 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, EX. PIPE | 1 | eBay Motors → |
| 19012-PD2-004 | O-RING, DRAIN (TOYO) | 1 | eBay Motors → |
| 19321-59B-004 | GASKET, THERMOSTAT CASE | 1 | eBay Motors → |
| 90012-59B-004 | NUT, SELF-LOCK (10MM) (CATALYST) | 4 | eBay Motors → |
| 90160-TZA-000 | BOLT, FLANGE (12X45) (SIDE MOUNT) | 2 | eBay Motors → |
| 90166-TBA-A00 | BOLT, FLANGE (14X64) (SIDE MOUNT) | 2 | eBay Motors → |
| 90171-TBA-A00 | BOLT, FLANGE (10X30) (SIDE MOUNT) | 3 | eBay Motors → |
| 90212-SA5-003 | NUT, SELF-LOCK (10MM) (EXHAUST) | 3 | eBay Motors → |
| 90371-SJD-003 | NUT, FLANGE (14MM) (SIDE MOUNT) | 1 | eBay Motors → |
| 91212-59B-003 | OIL SEAL (43X58X7) (CRANK SEAL) | 1 | eBay Motors → |
| 91311-5R1-J01 | HPFP O-RING | 1 | eBay Motors → |
| 91314-PH7-003 | O-RING | 2 | eBay Motors → |
| 10003-6NA-A00 | GENERAL ASSY., CYLINDER HEAD | 1 | eBay Motors → |
| 15815-6A0-A01 | FILTER ASSY., SPOOL VALVE | 1 | eBay Motors → |
| 16451-6MA-J01 | CLIP, INJECTOR | 1 | eBay Motors → |
| 16453-6MA-J00 | SEAL SET, INJECTOR | 1 | eBay Motors → |
| 19310-6A0-A01 | COVER ASSY., THERMOSTAT | 1 | eBay Motors → |
| 10002-6VJ-A00 | GENERAL ASSY., CYLINDER BLOCK | 1 | eBay Motors → |
| 18303-T2B-A01 | GASKET, EX. PIPE | 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 → |
| 90164-T20-A00 | BOLT, FLANGE (14X33) (TORQUE ROD) | 5 | eBay Motors → |
| 90175-TRW-A00 | BOLT, FLANGE (14X105) (TORQUE ROD) | 1 | eBay Motors → |
| 90215-SB0-003 | NUT, SELF-LOCK (12MM) (KNUCKLE) | 3 | eBay Motors → |
| 90471-59C-000 | GASKET (10MM) | 1 | |
| 90471-PX4-000 | WASHER, DRAIN PLUG | 1 | eBay Motors → |
| 91306-59B-003 | O-RING, WATER PASSAGE (WATER) | 1 | eBay Motors → |
| 91333-PNC-006 | CKP SENSOR O-RING | 1 | eBay Motors → |
| 90401-PR4-000 | WASHER, SEALING (28MM) (For vehicles with engine block heater only) | 1 |
Labour operation and the time the manufacturer allows
| Operation | Description | Time |
|---|---|---|
| 1105E2 | Inspect for coolant leaks. Remove cylinder head and check head and engine block for… | 11.1 hrs |
Read by machine from the document NHTSA serves (22 pages), read Oct 4, 2026. A part number is shown only where it matches Acura’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 2 model years this bulletin names have filed 5 complaints with NHTSA since 2015.
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 group3 other manufacturer communications filed against the Acura ADX under the same component group (engine), newest first.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| BBJA31120 | Service bulletin | Sep 14, 2026 | Job Aid - This job aid only applies to vehicles involved in the cylinder head gasket warranty extension. While replacing the cylinder head g… |
| BEBM08262026901 | Other | Aug 26, 2026 | Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience over… |
| B25-052 | Service bulletin | Sep 17, 2025 | Service Bulletin - Oil leak at the cam chain tensioner inspection cover due to and insufficient sealant adhesion on the inspection cover. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Acura, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is Acura B26-001 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 B26-001 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 B26-001 cover?
The manufacturer filed it against 2 model years: 2026 Acura ADX, 2025 Acura ADX. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.