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Service bulletins for the 2018 Honda Clarity

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.

46 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

Only bulletins with component: Fuel tank are shown. Show all

Bulletins, newest first
A20-0612020-10-29. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY. Service Bulletin - The MIL comes on with DTC P1FBF (air pump controller failure [internal failure warning]) during startup.
A20-0612020-09-09. Service bulletin. FUEL SYSTEM, OTHER:STORAGE:TANK ASSEMBLY. Service Bulletin - The MIL comes on with DTC P1FBF (air pump controller failure [internal failure warning]) during startup.
A19-054_version32020-04-16. Service bulletin. ELECTRICAL SYSTEM; FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY. Service Bulletin - The fuel cell (FC) system uses an electric water pump to circulate insulating fluid and remove excess heat from the fuel cell stack. During manufacturing, the water pump's magnetic surface was not treated for corrosion resistance. Over time, the corrosion may prevent the water pump's motor from starting, which will prevent the vehicle from starting. If this happens while driving, the vehicle can only be driven for a short distance at greatly reduced power.
A19-0062020-04-16. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; ELECTRICAL SYSTEM. Service Bulletin - Water improperly discharged inside the fuel cell (FC) stack mixes with hydrogen and oxygen, generating hydrogen peroxide. The hydrogen peroxide/water combination concentrates in one area, accelerating the deterioration of the electrolyte membrane in the fuel cell. This deterioration can reduce fuel cell output.
A19-0542019-06-12. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; ELECTRICAL SYSTEM. Service Bulletin - The fuel cell (FC) system uses an electric water pump to circulate insulating fluid and remove excess heat from the fuel cell stack. During manufacturing, the water pump's magnetic surface was not treated for corrosion resistance. Over time, the corrosion may prevent the water pump's motor from starting, which will prevent the vehicle from starting. If this happens while driving, the vehicle can only be driven for a short distance at greatly reduced power.
A19-0062019-06-12. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; ELECTRICAL SYSTEM. Service Bulletin - Water improperly discharged inside the fuel cell stack mixes with hydrogen and oxygen, generating hydrogen peroxide. The hydrogen peroxide/water combination concentrates in one area, accelerating the deterioration of the electrolyte membrane in the fuel cell. This deterioration can reduce fuel cell output.
ONL6CK030520192019-03-15. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; FUEL SYSTEM, OTHER:STORAGE:TANK ASSEMBLY. Owner Notification Letter - On 2017-18 Clarity Fuel Cell vehicles, the software that monitors the temperature in the fuel cell tank may not be up to date. This may cause the vehicle to incorrectly display a hydrogen system warning on the instrument panel and store a system malfunction.
A19-0062019-02-21. Service bulletin. FUEL SYSTEM, OTHER:STORAGE:TANK ASSEMBLY. Service Bulletin - The telematics system is reporting deterioration of the fuel cell stack. This deterioration can reduce fuel cell output. Water improperly discharged inside the fuel cell stack mixes with hydrogen and oxygen, generating hydrogen peroxide. The hydrogen peroxide/water combination concentrates in one area, accelerating the deterioration of the electrolyte membrane in the fuel cell.
A19-0062019-02-10. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; ELECTRICAL SYSTEM. "Service bulletin - The telematics system is reporting deterioration of the fuel cell stack. This deterioration can reduce fuel cell output. Water improperly discharged inside the fuel cell stack mixes with hydrogen and oxygen, generating hydrogen peroxide. The hydrogen peroxide/water combination concentrates in one area, accelerating the deterioration of the electrolyte membrane in the fuel cell."

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.