2021 Honda Clarity Problems: 4 Known Issues
2021 model year · 630+ owner reports · Updated October 2026
According to Au7o's analysis of 630+ owner reports, the 2021 Honda Clarity has 4 documented known issues, with 1 rated critical. The most serious is Sudden Power Loss and Engine Over-Rev on Highway ($0-$150 repair). The most commonly reported issue is 12V Auxiliary Battery Drain When Vehicle Sits Idle with 210 owner reports. Across all issues with published estimates, repair costs range from $25 to $1,200. DIY maintenance guides at au7o.io.
2021 · All trims · All engines
Choose the year and equipment for your written issues and visual request.
No email neededHow interest is saved
Interest applies to the selected vehicle and configuration; it is not a reservation. Voting stores a first-party identifier for up to 180 days to prevent repeat votes. No account or email is needed. Clearing cookies or using another device may count separately. Privacy
Visual coming soon
Your interest helps us choose what to build next.
Visual Known Issues · Coming soon
$4.99/month plus taxes at launch · No payment today
All 4 Known Issues
Join 600+ people using Au7o to better understand their vehicles.
Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.
Other Honda Models
Frequently Asked Questions
What are the most common Honda Clarity problems?
According to Au7o's analysis of 630+ owner reports, the 2021 Honda Clarity has 4 documented issues. The most frequently reported are: Sudden Power Loss and Engine Over-Rev on Highway, Intermittent Charging Failure and Battery Not Fully Charging, AC Condenser Refrigerant Leak and Cooling System Failure. Of these, 1 is rated critical and should be addressed promptly.
Is the Honda Clarity reliable?
The 2021 Honda Clarity has 4 known issues documented across 630+ owner reports. 1 issue is rated critical: Sudden Power Loss and Engine Over-Rev on Highway. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
How much does it cost to fix common Honda Clarity problems?
Repair costs for known Honda Clarity issues range from $0 to $1,200, depending on the specific problem and whether you choose DIY or professional repair. The most critical issue, Sudden Power Loss and Engine Over-Rev on Highway, typically costs $0-$150 to repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.
What is the 2018-2021 Honda Clarity Sudden Power Loss and Engine Over-Rev on Highway?
The Honda Clarity PHEV can experience a dangerous loss of power when transitioning from electric to gasoline engine operation, particularly under high-load conditions such as highway hills, cold weather, or when the battery is nearly depleted. The vehicle may drop from highway sp… Repairs typically run $0-$150. Severity: high.
What is the 2018-2021 Honda Clarity Intermittent Charging Failure and Battery Not Fully Charging?
The Honda Clarity PHEV may fail to start charging when plugged in, or may stop charging before the high-voltage lithium-ion battery reaches full capacity. The onboard charger or charging control software may not properly communicate with the EVSE (charging station), resulting in… Repairs typically run $0-$300. Severity: medium.
What is the 2018-2021 Honda Clarity AC Condenser Refrigerant Leak and Cooling System Failure?
The Honda Clarity PHEV is prone to AC condenser failures caused by refrigerant leaks. The condenser, located in front of the radiator, develops leaks mainly from corrosion (Honda says the condenser was not manufactured to specification, allowing tiny holes to form in the tube wal… Repairs typically run $600-$1,200. Severity: medium.
What is the 2017-2021 Honda Clarity 12V Auxiliary Battery Drain When Vehicle Sits Idle?
The Honda Clarity PHEV and EV models experience 12V auxiliary battery drain when the vehicle is not driven for extended periods (7-14 days). Unlike conventional vehicles, the Clarity's 12V battery is relatively small and powers multiple always-on systems including the telematics… Repairs typically run $25-$250. Severity: low.
Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.