Equipment: electrical
Free remedy
Honda (American Honda Motor Co.) is recalling certain 2017-2018 Clarity Fuel Cell vehicles. Internal components may corrode and cause the water pump to fail.
Research · Midsize Cars · 2 NHTSA variants
2018 Honda ClarityRecalls, problems, MPG & safety
NHTSA lists 2 safety recalls and 26 owner complaints for the 2018 Honda Clarity. Most complaints involve electrical system (5) and engine (4). The EPA rates it 68–114 mpg combined.
Combined MPG
68–114mpg
EPA · 2 versions
NHTSA overall
—
Not rated by NCAP
Safety recalls
2campaigns
Latest Apr 2019
Owner complaints
26
Top: electrical system
Fuel cost / yr
$650est.
EPA estimate, best version
Safety recalls
2 NHTSA campaigns · applies to some vehicles, check your VIN
Electrical system: software
Free remedy
Honda (American Honda Motor Co.) is recalling certain 2017-2018 Clarity Fuel Cell vehicles previously repaired under recall 18V-068. The previous software remedy may have been incomplete. As a result, the fuel cell control unit (FC-ECU) may misinterpret a small cell voltage drop, causing the vehicle to have a partial or complete loss of power.
Data from NHTSA Recalls API · synced Nov 14, 2026 · All recall detailsNHTSA vehicle page
Owner complaints by component
26 complaints filed with NHTSA · Apr 2018 – Jan 2026
- Electrical system5
- Engine4
- Service brakes4
- Visibility/wiper4
- Fuel/propulsion system4
- Power train3
- Forward collision avoidance3
- Lane departure2
- Vehicle speed control2
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
Data from NHTSA Complaints API · synced Nov 14, 2026 · Full problem breakdownNHTSA vehicle page
What owners report most
Verbatim excerpts from NHTSA complaints, by component
Electrical system
5 reports
“The vehicle exhibits a dangerous electrical defect involving uncontrolled power-cycling. After shutting down the car, it automatically restarts itself in a continuous loop. During these episodes, the dashboard flickers, the drivetrain shudders, and the vehicle becomes unresponsive to manual 'Stop' button or brake inputs. Most critically, the car autostarts while parked in an enclosed garage. As a Plug-in Hybrid (PHEV), once the EV battery depletes, the internal combustion engine (ICE) engages automatically. This creates a life-threatening risk of Carbon Monoxide (CO) poisoning for residents in the connected home. A Honda dealership has professionally diagnosed the cause as a failure of the Body Control Module (BCM). This module failure also causes the anti-theft alarm to trigger uncontrollably and renders the keyless entry system inoperable. This defect turned the vehicle into a life-safety hazard in a residential setting. Visual documentation of the uncontrolled power-cycling and dashboard flickering can be viewed at: [XXX]”
Engine
4 reports
“The engine revs very high and the car dramatically slows down. This has happened three times (including today) in the two years I have owned the car. Once was extremely dangerous as it happened on an Interstate highway when traffic was at highway speeds. We were able to avoid getting in an accident though. Why is there no recall for this common problem with this car?”
Service brakes
4 reports1 crash
“Since last Wed. (9/24/2025), the car started to show the warnings of "Adaptive Cruise Control Problem", "Brake Hold System Problem", "Brake System Problem", "Electric Parking Brake Problem", and "Road Departure Mitigation System Problem" from time to time. I bought this VHonda Clarity Plug-in Hybrid 2018 in June 2023 as the HoneTrue Certified. Then probably the same time, the car lose the EV mode by itself, and only drives in the gas mode. I found this issue and late manually changed it to EV mode. WHile then it again dropped the EV mode during the driving today (9/28/2025). When I tried to press the EV button, it shows "Drive Mode Change Unavailable"! After stopped at home, I re-started the car, I can change it to EV mode.”
Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 14, 2026
Engines, transmissions & drive
2 versions rated by the EPA
- EPA class
- Midsize Cars
- Engines
- Electric motor · fcv
- Transmissions
- Automatic (A1)
- Drive
- Front-Wheel Drive
- Fuel
- Electricity · Hydrogen
- EV range
- 366 mi (EPA)
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
Data from EPA fueleconomy.gov · synced Nov 14, 2026EPA listing
EPA fuel economy by version
City / highway / combined, annual fuel cost and CO₂
EPA
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| Clarity EV Auto (A1) · Front-Wheel Drive | 126 | 103 | 114 | $650 | — |
| Clarity FCV Auto (A1) · Front-Wheel Drive | 69 | 67 | 68 | — | — |
- 114mpg comb.
- 68mpg comb.
Data from EPA fueleconomy.gov · synced Nov 14, 2026 · Fuel cost is EPA’s annual estimate (15,000 mi, 55% city)
NHTSA 5-Star Safety Ratings
2 tested variants
NHTSA has not published 5-Star Safety Ratings for the 2018 Honda Clarity as of Nov 14, 2026.
Maintenance basics
General guidance, not the OEM schedule. Check your owner’s manual.
General guidance
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
- Engine oil & filter5,000–10,000 mi
6–12 months - Tire rotation5,000–7,500 mi
Every oil change - Engine air filter15,000–30,000 mi
1–2 years - Cabin air filter15,000–25,000 mi
1–2 years - Brake fluid—
2–3 years - Coolant60,000–100,000 mi
5–10 years - Spark plugs60,000–100,000 mi
— - 12V battery—
3–5 years
Typical intervals for modern cars. Severe service (towing, short trips, extreme heat or cold) shortens them.
2018 Clarity questions
How many recalls does the 2018 Honda Clarity have?
2 safety recalls as of Nov 14, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
What are the most common 2018 Honda Clarity problems?
Owners filed 26 complaints with NHTSA. The most-cited components are electrical system (5), engine (4), service brakes (4). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
What MPG does the 2018 Honda Clarity get?
The EPA rates the 2018 Honda Clarity at 68–114 mpg combined, depending on engine and drivetrain (2 versions rated).
Data from NHTSA & EPA · synced Nov 14, 2026