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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

Bulletins, newest first
A18-0902023-11-29. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. Service Bulletin - There is a software problem in the PCM, which may cause the MIL to come on with DTC P26A3 (electric water valve malfunction), DTC P100C (electric VTC motor speed signal circuit malfunction) and/or P0010 (variable valve timing control [VTC] malfunction). There are up to three updates that must be performed on applicable vehicles.
ONL6CK092120222022-09-27. Service bulletin. ELECTRICAL SYSTEM. Owner's Notification Letter - Product Update - Our records indicate that a Product Update has not been completed on this vehicle (Vehicle Identification Number XXXXXXXXXXXXXXXXX). 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.
ONL6PH091520222022-09-22. Service bulletin. FUEL SYSTEM, GASOLINE; ELECTRICAL SYSTEM. Owner's Notification Letter - Our records indicate that a PRODUCT UPDATE has not been completed on this vehicle (Vehicle Identification Number [VIN NUMBER]). On Clarity Plug-in Hybrid vehicles, there is a software error in the miles per gallon calculation, which affects the HV range display and causes it to read unusually high.
A22090A2022-09-22. Service bulletin. ELECTRICAL SYSTEM. Dealer Message - In the event you experience a sub tank wire harness rodent damage on the 2017–2020 Clarity FCV, after repairing / replacing the wire harness, wrap the areas shown below with RODENT DETERRENT TAPE, P/N 4019-2317.
ONLO9V070620212021-07-21. Service bulletin. VISIBILITY. Owner Notification Letter - On some 2018-21 Clarity Plug-In Hybrid models, the A/C condenser may leak refrigerant. American Honda is extending the warranty on the A/C condenser to 10 years from the original date of purchase with unlimited miles. This warranty extension provides coverage for the original owner and any subsequent owners. No action is required on your part unless you experience a problem.
ABOM052820212021-06-03. Service bulletin. VISIBILITY. Dealer Message - Today, May 28, 2021, American Honda is announcing a warranty extension for certain 2018-2020 Accord and Accord Hybrid, 2018-2020 Civic, 2017-2021 Civic Hatch, 2017-2021 Civic Type R, 2018-2021 Clarity PHEV, and 2019-2021 Insight vehicles. This warranty extension covers the A/C condenser to address concerns of leaking refrigerant. American Honda is extending the warranty on the A/C condenser to 10 years from the original date of purchase.
A21-0172021-06-03. Service bulletin. VISIBILITY. Service Bulletin - American Honda is extending the warranty on the A/C condenser to 10 years from the original date of purchase with unlimited miles. This warranty extension only covers vehicles that have a defective A/C condenser from the factory. The A/C condenser was not manufactured to specification. As a result, corrosion may develop in the form of tiny holes in the condenser tube walls that allow the refrigerant to leak out. This does not apply to any vehicle that has a leaking condenser due to foreign object damage. It also does not apply to any vehicle that has ever been declared a total loss or sold for salvage by a financial institution or insurer, or has a branded or similar title under any state's law.
A21-0082021-02-18. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING. Service Bulletin - The Hybrid System Failure message comes on the MID, and DTC P1D8D (Generator Motor Inverter Short) is stored.
A20-0922020-12-19. Service bulletin. FUEL SYSTEM, GASOLINE. Service Bulletin - The customer cannot refuel the vehicle completely at certain hydrogen stations.
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.
A18-0902019-10-29. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; VISIBILITY. Service Bulletin - There is a software problem in the PCM, which may cause the MIL to come on with DTC P26A3 (electric water valve malfunction), DTC P100C (electric VTC motor speed signal circuit malfunction) and/or P0010 (variable valve timing control [VTC] malfunction).
APOC062720192019-07-04. Service bulletin. VISIBILITY; ELECTRICAL SYSTEM. Dealer Message - On October 4, 2018, American Honda announced several Product Update Campaigns for certain 2018 Honda Clarity Plug-In Hybrid (PHEV) models. Replacement CPU Assembly Auto AC Kits and Warranty CD's were available at the time of bulletin launch.
A19-054_version22019-06-19. Service bulletin. 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.
A19-0542019-06-12. 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.
A19050B2019-05-30. Service bulletin. STEERING. ServiceNews Article - When removing and installing a cable reel, you need to keep both the cable reel and the steering angle sensor in position. If you don't , the VSA indicator may come on along with one or more VSA DTCs. And when you run the Neutral Memorization Procedure in the i-HDS, it won't complete.
ONL6VT032620192019-04-06. Service bulletin. ENGINE AND ENGINE COOLING; VISIBILITY; POWER TRAIN. Owner Notification Letter - On Clarity Plug-in Hybrid vehicles, there may be a software problem in the powertrain control module (PCM), causing a malfunction indicator light to come on and store one or more diagnostic trouble codes (DTCs).
ONL6SV032620192019-04-06. Service bulletin. ENGINE AND ENGINE COOLING; VISIBILITY. Owner Notification Letter - On Clarity Plug-in Hybrid vehicles, there is a software problem in the climate control unit when running the heater, which may turn the malfunction indicator light on.
ONL6PH032620192019-04-06. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY. Owner Notification Letter - On Clarity Plug-in Hybrid vehicles, there is a software error in the miles per gallon calculation, which affects the HV range display and causes it to read unusually high.
ONL6CW032620192019-04-06. Service bulletin. ELECTRICAL SYSTEM. Owner Notification Letter - On Clarity Plug-in Hybrid vehicles, the warranty information CD that was placed in the vehicle during vehicle assembly did not list the correct warranty coverage for the state of Oregon.
A18-0972019-03-19. Service bulletin. ELECTRICAL SYSTEM; ELECTRICAL SYSTEM:12V/24V/48V BATTERY. Service Bulletin - The Clarity Plug-In Hybrid and Clarity Electric may not start charging when plugged in or may stop charging before the high-voltage lithium-ion battery is full.
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.

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