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Service bulletin A26-009

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id11036408
Published by NHTSA2026-08-27
Manufacturer's numberA26-009
Manufacturer's date2026-08-26
NHTSA componentENGINE

NHTSA's summary

Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine

Trouble codes named

P0300, P0304

Vehicles listed
HONDA CIVIC2016, 2017, 2018, 2019, 2020, 2021
HONDA CIVIC SI2017, 2018, 2019, 2020 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Recalls for the same vehicles and component
16V0740002016-02-09. ENGINE AND ENGINE COOLING:ENGINE
20160472016-02-01. Engine

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
A26-0992026-10-01. Service bulletin. Service 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).
A26-0972026-10-01. Service bulletin. Service 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).
A26-0092026-10-01. Service bulletin. Service 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).
A26-0082026-10-01. Service bulletin. Service 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).
A26-0992026-09-02. Service bulletin. Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire, and/or DTCs P0300 thru P0304 stored.
A26-0972026-09-02. Service bulletin. Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire, and/or DTCs P0300 thru P0304 stored.
AEBM082620269012026-08-27. Other. Dealer Message - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire, and/or DTCs P0300 through P0304 stored.
A26-0992026-08-27. Service bulletin. Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
A26-0972026-08-27. Service bulletin. Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.
A26-0082026-08-27. Service bulletin. Service Bulletin - Under certain conditions, the cylinder head gasket effectiveness may be reduced which may cause vehicles to experience overheating, coolant loss, misfire and/or DTCs P0300 thru P0304 stored.