Owners have filed 11 complaints
about the 2021 Toyota Prius with NHTSA between 2021 and 2026.
The largest single group is the engine & cooling.
Across this model's run it ranks 18 of 25 worst.
The letter says how bad. This says what kind — whether this year drew
an unusual number of complaints, unusually dangerous
ones, or failures that arrived unusually early.
The dashed ring is 50 — the national norm. Further out is worse.
Complaint volume — 1
Against the median year of the Toyota Prius. 50 means typical for this
model; 100 means roughly double.
Severity — 100
27.3% of these complaints
involved a crash, fire, injury or death, against a national rate of
9.7%.
Early failure — 100
80% of failures with a mileage on record happened under
36,000 miles, against a national rate of
29%.
Complaints filed with NHTSA, by model year. Bar colour is the FaultScore grade:
A
B
C
D
F
ungraded
What breaks on a 2021 Toyota Prius
Every complaint is filed against a part. Follow any row for the complaints about that part alone.
Driver Assist & Collision Avoidance
218.2%
Fuel & Propulsion
218.2%
Median failure at 5,200 miles
Engine & Cooling
218.2%
1 crashes, 0 fires · median 5,200 mi
Other & Unspecified
19.1%
Median failure at 5,200 miles
Wheels
19.1%
Median failure at 190 miles
Acceleration & Cruise Control
19.1%
Median failure at 56,000 miles
Brakes
19.1%
1 crashes, 0 fires
Electrical System
19.1%
1 crashes, 0 fires
When it fails
Odometer readings owners gave when they filed. About half of all
complaints include one.
Under 1,000 miles
120.0%
1,000 – 9,999 miles
360.0%
50,000 – 74,999 miles
120.0%
When owners complained
A spike years after the car went on sale usually means a part wearing
out on schedule across the whole fleet — the kind of pattern no single
owner can see from inside their own car.
Mar 2021peak 3Feb 2026
NHTSA investigations into the 2021 Toyota Prius
An investigation is the step before a recall: the agency has seen enough
complaints to look into a pattern itself. An open one means it thinks
something may be wrong and nothing has been fixed yet.
DP22005Opened 27 Jan 2023Closed 7 Aug 2023ELECTRICAL SYSTEM:PROPULSION SYSTEM
Pedestrian alert sounds
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles. The standard applies to hybrid and electric vehicles that have a gross vehicle weight rating of 4,536 KG or less or are defined as low-speed vehicles. The standard became fully applicable to all such vehicles manufactured on or after Marc...
Complaints that involved harm
Reports where the owner recorded a crash, a fire, an injury or a death.
Mountain Top, PACrash
ELECTRICAL SYSTEM
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
Mountain Top, PACrash
ENGINE
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
Mountain Top, PACrash
SERVICE BRAKES
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
The most recent complaints
In the owners' own words, exactly as filed with NHTSA.
Amman, NC
FUEL/PROPULSION SYSTEM
When i am going down it's charging when the charge reaches 6 from 8 the engine starts working and stop changing at that point and the power continues comes from engine only without the hybrid battery and there are no codes
NHTSA complaint #11719876 — an unverified report by a vehicle owner.
at 56,000 milesFox Lake, IL
VEHICLE SPEED CONTROL
The contact owns a 2021 Toyota Prius. The contact stated while driving approximately 35 - 45 MPH, the vehicle independently accelerated. The brake pedal was depressed but failed to stop the vehicle immediately. The contact swerved around the vehicle in front and ended up on the opposite side of the roadway. The contact attempted to avoid oncoming traffic and swerving around all the other vehicles and ended up in a ravine. The contact's husband depressed the START/STOP button from the passenger’s side to turn off the vehicle, enabling the vehicle to come to a stop. The contact restarted the vehicle and continued to drive the vehicle to the dealer at slow speeds. The dealer was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was made aware of the failure by the dealer. The failure mileage was 56,000.
NHTSA complaint #11615271 — an unverified report by a vehicle owner.
Carlisle, PA
FORWARD COLLISION AVOIDANCE: ADAPTIVE CRUISE CONTROL
The Lane keeping assist used in radar cruise control mode during some drive cycles will attempt to maintain the vehicle position to the far extreme of the lane and in some cases actively veer out of the lane. My safety ant others can be put at risk when the vehicle behaves outside of its design parameters like this. To solve the issue the vehicle must be pulled over, turned off, then restarted. After the restart it will resume functioning normally, maintaining lane positioning as intended within the limits of the system. The trigger for this is unknown but could be speculated that it is drive cycle dependent and may start during initialization. The problem has not been reproduced by a dealer or service center due to its intermittent nature. There are no warning indicators or lamps on when this occurs.
NHTSA complaint #11532235 — an unverified report by a vehicle owner.
Carlisle, PA
LANE DEPARTURE: ASSIST
The Lane keeping assist used in radar cruise control mode during some drive cycles will attempt to maintain the vehicle position to the far extreme of the lane and in some cases actively veer out of the lane. My safety ant others can be put at risk when the vehicle behaves outside of its design parameters like this. To solve the issue the vehicle must be pulled over, turned off, then restarted. After the restart it will resume functioning normally, maintaining lane positioning as intended within the limits of the system. The trigger for this is unknown but could be speculated that it is drive cycle dependent and may start during initialization. The problem has not been reproduced by a dealer or service center due to its intermittent nature. There are no warning indicators or lamps on when this occurs.
NHTSA complaint #11532235 — an unverified report by a vehicle owner.
Mountain Top, PACrash
ELECTRICAL SYSTEM
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
Mountain Top, PACrash
ENGINE
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
Mountain Top, PACrash
SERVICE BRAKES
The car accelerated without my foot on the accelerator, brake did not respond, and I had to drive through grass and a rock-filled ditch until after about 10 seconds the car returned to my control.
NHTSA complaint #11526893 — an unverified report by a vehicle owner.
at 5,200 milesPalm BAY, FL
UNKNOWN OR OTHER
CARBON MONOXIDE SEEPS INTO THE PASSENGER CAR BUT DILLER CANNOT FIND IT AND DID NOT HAVE TOOLS TO DETECT CO LEVEL IN THE CAR. I CAN'T USE THIS CAR BECAUSE WAS POISONED MANY TIMES AND AFTER A SECOND CHECK-UP, THE LEVEL OF CO BECOMES HIGHER SO I CAN'T DRIVE THE CAR WITHOUT POISONING. PLEASE HELP ME. I AM WORRYING TO SELL MY CAR BECAUSE OTHER DRIVER WILL GET INJURY. THIS IS THE NEW CAR ONLY 7000 MILES.
NHTSA complaint #11416154 — an unverified report by a vehicle owner.
at 5,200 milesPalm BAY, FL
ENGINE
CARBON MONOXIDE SEEPS INTO THE PASSENGER CAR BUT DILLER CANNOT FIND IT AND DID NOT HAVE TOOLS TO DETECT CO LEVEL IN THE CAR. I CAN'T USE THIS CAR BECAUSE WAS POISONED MANY TIMES AND AFTER A SECOND CHECK-UP, THE LEVEL OF CO BECOMES HIGHER SO I CAN'T DRIVE THE CAR WITHOUT POISONING. PLEASE HELP ME. I AM WORRYING TO SELL MY CAR BECAUSE OTHER DRIVER WILL GET INJURY. THIS IS THE NEW CAR ONLY 7000 MILES.
NHTSA complaint #11416154 — an unverified report by a vehicle owner.
at 5,200 milesPalm BAY, FL
FUEL/PROPULSION SYSTEM
CARBON MONOXIDE SEEPS INTO THE PASSENGER CAR BUT DILLER CANNOT FIND IT AND DID NOT HAVE TOOLS TO DETECT CO LEVEL IN THE CAR. I CAN'T USE THIS CAR BECAUSE WAS POISONED MANY TIMES AND AFTER A SECOND CHECK-UP, THE LEVEL OF CO BECOMES HIGHER SO I CAN'T DRIVE THE CAR WITHOUT POISONING. PLEASE HELP ME. I AM WORRYING TO SELL MY CAR BECAUSE OTHER DRIVER WILL GET INJURY. THIS IS THE NEW CAR ONLY 7000 MILES.
NHTSA complaint #11416154 — an unverified report by a vehicle owner.
at 190 milesLakeland, FL
WHEELS
WHILE DRIVING ON THE I 4 WE HAD A BLOWOUT ON THE REAR PASSENGER TIRE. THE CAR HAD LESS THAN 200 MILES ON IT SO IT WAS BRAND NEW. THE DEALERSHIP FOUND OBJECT IN THE TIRE THAT COULD HAVE CAUSE THE PROBLEM THE ONLY CONCLUSION I COULD COME TO IS THAT THIS TIRE WAS DEFECTIVE. THE DEALERSHIP SAID I COULD HAVE RUN OVER A LARGE OBJECT OR A LARGE POTHOLE, WHICH I DOUBT.
NHTSA complaint #11404863 — an unverified report by a vehicle owner.