# the federal safety agency VEHICLE SAFETY COMPLAINT **Subject: Sudden Unintended Braking, Violent Vehicle Bucking, and Loss of Propulsion – 2020 Honda Clarity Plug-In Hybrid** **Vehicle Information** - Manufacturer: Honda - Model: Clarity Plug-In Hybrid - Model Year: 2020 - Mileage: Approximately 35,000 miles - Incident Date: October 2026 (exact date to be confirmed) - Incident Location: [XXX] - Servicing Dealership: DCH Paramus Honda, [XXX] - Vehicle Identification Number (VIN): [Insert VIN] ## Description of Safety Incident I am reporting a serious and potentially life-threatening vehicle safety malfunction involving my 2020 Honda Clarity Plug-In Hybrid, which experienced sudden, unintended, violent braking and a subsequent severe loss of propulsion while traveling on a public roadway. The incident occurred approximately five minutes after I picked up my vehicle from DCH Paramus Honda, an authorized Honda dealership, following a warranty-covered replacement of the air-conditioning condenser. The vehicle had approximately 35,000 miles and was operating normally before this repair. While driving home to [XXX], at the intersection of [XXX], my vehicle suddenly and unexpectedly began violently jerking and bucking, with the wheels seemingly locking, before coming to an abrupt stop. **There was no vehicle, pedestrian, or other obstacle directly ahead of my car. The roadway was clear, and there was no apparent reason for emergency braking.** I did not intentionally activate the emergency parking brake or initiate an emergency stop. Immediately following this event, numerous dashboard warning indicators illuminated, including the following specific messages: - **Collision Mitigation Braking System Problem** - **Power System Problem** The vehicle was initially unable to function normally. After restarting it, the car operated only at severely reduced power, with a m INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
Honda Clarity Plug-In Hybrid loss of power problems
19 of the 189 owner complaints about the Honda Clarity Plug-In Hybrid describe sudden loss of power, most of them for the 2018 model year.
- owner complaints
- 19
- worst model year
- 2018
- typical mileage
- 895
By model year
Often reported together
What owners say
I will first start with our problems/concerns. We had experienced a complete lost power in freeway speed (65 mph) when the battery is depleted, that is when the battery bar goes to zero bar instead of 2 bars usually. I attached a photo from the video I took for your reference. This experience was the engine ramp up and not getting any power while driving on freeway, escpecially obvious during uphill slope. It is a safety hazard where we had to manuver in order avoid traffic since we could not maintain freeway speed. This originally happened around 2022, but we checked with Norm Reeves Honda Cerritos and they told us nothing is wrong and because there was no fault code, nothing they can do. When the Recall service canoaign 24-031 came, we were relieved because we think the problem is going to be fixed. We brought our Honda Clarity to the dealer on 2/3/2025 for the recall and everything was fine (meaning we can drive on HV after our battery is depleted). But around December 2025, my wife experienced the same situation where she couldn’t keep up with the freeway speed after exhausted the electric range of 34 miles. We took it to dealer again on 1/16/2026 and described the situation, dealer came back and said nothing has been found and there were no fault code. After that, the only way that we are trying to do is to avoid the battery to get down to zero miles, but since our battery is only getting 34 miles full charge instead of the 47 miles when it was new (dealer also said this is normal depreciation, I am not sure about that). Again, thank you for helping since losing engine power and speed on freeway is pretty scary and I hope this is enough information for my case. Here are answers to your questions. VIN: [XXX] Mileage: 85300 Dealership: Norm Reeves Honda Cerritos Details: Vehicle losing power on freeway speed after battery is depleted. As described above. First time it happened: Around 2022 First time dealer address my concern rather than told me th INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION A
Few times it has happened especially in extreme cold weather, there will be loss of power/acceleration even though you are trying to accelerate the vehicle. While accelerating it will take the command engine RPM will be higher but vehicle is not taking up the speed. Either it will stay to go at low speed or slowly it will starting to halt situation. This has happened few times(about 5-6 times). And in such situation there will some unacceptable noise from engine. One time we were at about 50mph speed but I couldn't accelerate (just like above) and had to stop the car in middle of highway, stop the car (shut the engine) and then start the car it started working fine. This happened mostly when on gas and especially during extreme cold weather. While on fully EV mode it works fine, I have never experienced this problem.
When the battery is low the honda clarity's RPM jump really high and vehicle revs really hard and starts to lose power. My vehicle had two battery bars and when I tried to climb it mountain it lost speed. I was almost hit twice because my car kept losing speed and it was revving like it was struggling to keep moving. Very scary situation to be in with other cars and little children in my car. I have a video of the car revving.
7.25.2020 - when car is running for 45 minutes, 85 degrees f, EV on, econ off, engines loses power and revs high after 40mph. 7.18.2020 - when car is running for 45 minutes, 89 degrees f, EV off, econ on, engines loses power and revs high after 40mph. 2015 toyota prius plug-in had the similar issue of the car losing power after driving faster than 62 MPH with EV mode on. A relay switch recall occurred that fixed this issue.. So far.
July 4, 2020 drove with our family of 2 babies on a local highway with a maximum speed of 50mph and traveling a round-trip distance of 52 miles. Outside temperatures were about 89℉. After driving for about 20 minutes, the engine would rev at a high RPM at 40mph. It could be heard and felt over the radio's music. Giving more gas didn't make the car drive faster. On the way home, about 40 minutes into the drive, the engine revved high again at 40mph, lost of power, and this time making the car's speed slow to 30mph because we were approaching a red light, luckily. This issue occurred before on july 27,2020 when my wife drove the car and conplained about it driving slow and engine revving loud. This car has only 1,884 miles on it and was bought in january 2020. Lemon law.
My car is losing power and getting loud noise while driving on an uphill road. I have shown my car to 3 different dealers and they couldn't fix it. I have seen many online reviews with the same problem and still, honda is not helping its customer.
Three times now, our new 2019 honda clarity has put me and my family in danger. Twice in november 2019, once in january 2020, the car suddenly lost power in the midst of driving up hills, once at highway speed. Each time the car has produced a terrible burning smell and sounds of high revving of the engine. In all of these instances, the battery was low, but the gas level and reported range of the car was high. Once the car was in eco mode, twice it was in other modes. We have been to the dealer 3 times, and they have been in touch with national honda, who say that these symptoms are a 'normal characteristic' and that 'proper drive modes should be used,' as if the problem was somehow my fault for not using the proper modes. I was sent a very short video explaining driving modes. If this car is designed so that sudden loss of power, burning smells and an inability to drive up a hill are a 'normal characteristic' then this car is a hazard. If the car is unable to go up a steep hill without a certain battery level, then the car should not be designed to deplete the battery below that level no matter what mode the driver has it in. If the honda solution to the problem is for me to use modes to keep the battery over 60% charged at all times, (which is what they suggested the second time I went in) or to stay off of hills when the battery is low (as they suggested when I brought it in the 3rd time) then it is not the plug-in car with the driving range I thought I was buying. Here is detail on the last incident: I was on a highway on a big hill at full highway speed when suddenly the power gave out and the car started revving in an extreme way, and there was a terrible burning smell. Luckily, I was in the right lane and was able to pull off the highway quickly. My passenger and I were both shaken ' this car is a danger until this problem is fixed.
Tl* the contact owns a 2019 honda clarity plug-in hybrid. When the vehicle switched from running on the battery to fuel, the vehicle lost power. In addition, the engine ran on very high rpms and the vehicle lost power without warning and came to a complete stop while driving 65 MPH. The contact coasted the vehicle to the side of the road and powered off the engine. The vehicle was restarted, but the failure recurred. The contact stated that the failure recurred twice, but the vehicle was not taken to a dealer or an independent mechanic for diagnostic testing. The manufacturer was not made aware of the failure. The failure mileage was approximately 100.
Tl* the contact owns a 2018 honda clarity plug-in hybrid. While driving 5 MPH, the battery was depleted and the engine mode engaged; however, the vehicle lost power and failed to accelerate. The vehicle was recharged and worked as designed. The engine system, adaptive cruise control, road departure, and power steering warning indicators were illuminated. The vehicle was not diagnosed or repaired. The manufacturer and dealer were not contacted. The failure mileage was 3,700. The VIN was invalid.
Related recalls
No recalls on record for this model year.
Questions about the Honda Clarity Plug-In Hybrid loss of power
Which Honda Clarity Plug-In Hybrid years have sudden loss of power problems?
The model years with the most reports are 2018 (11 complaints), 2019 (6 complaints) and 2020 (2 complaints).
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