Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Toyota Highlander owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, there was a whining sound coming from the vehicle. There was no warning light illuminated. The vehicle was taken to the dealer, where it was diagnosed with transmission failure. The dealer stated that the transmission needed to be replaced. The vehicle was repaired. After the vehicle was parked and turned off, there was transmission fluid leaking from the vehicle. There was no warning light illuminated. The vehicle was taken back to the dealer, where it was diagnosed and determined that the head gasket had failed and needed to be replaced. The vehicle was repaired. The contact then noticed fluid leaking from the transfer case while the vehicle was parked and turned off. …
The Check Engine light came on and I took it into Toyota of Downtown dealership where I was receiving periodic maintenance. After 2 days, they said the light was out but they hadn't found the cause. I could either leave if for a few more days or take it and bring it back if the light came on again. This was early August. I chose to take the car & when the Check Engine warning light came on again, I took it in on Aug 15, 2024 before I left to Portland to give them more time. I returned on Monday & couldn't reach them. The next day they informed me that while on a test drive, there was a loud bang, it started smoking and by the time 911 arrived it was on fire. After a 2 month investigation by Toyota's Engineering Analysis fire inspection, they concluded Toyota was not involved. …
Upon attempting to engage the brakes, it was found that they did not work. Immediately thereafter, the car began an uncommanded full acceleration. The insurance company has totaled the car. Our safety as occupants was obviously at serious risk. The driver chose to take the car off the road rather than jeopardize the lives of others on the same road. The car plowed through boulders and trees, coming to rest upside down wedged between an earthen berm and a tree......suspended about 2 feet above the ground. There were no warnings prior to the incident. The car has been inspected by the insurance company, and has been authorized for inspection by the manufacturer. There were no serious injuries as a result of the accident. We were VERY lucky! Uncommanded acceleration without any control is a frightening event any time....but definitely in the vicinity of other vehicles full of families.
The contact owns a 2021 TOYOTA HIGHLANDER. The contact stated while driving approximately 50 mph, the vehicle stalled without warning. The contact restarted the vehicle and pulled over to the side of the roadway before the vehicle stalled again. The contact was unable to restart the vehicle. The contact stated that the check engine warning light was illuminated. The vehicle was towed to the local dealer but was not yet diagnosed. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 230. The consumer stated that Sansone Toyota falsely stated bad gas was added to the vehicle. Sansone advised consumer to contact insurance company. Geico investigated the claim and agreed a warranty should be issued. The consumer stated that a new engine is needed and had to pay $2799.03.
The contact owns a 2021 Toyota Highlander. While driving 20 MPH uphill, the messages "Engine Failure," "Brake Failure," and "Pull Over to A Safe Place, See Owner's Manual" were displayed, and several unknown warning lights illuminated. The contact turned off and restarted the vehicle, but the failure persisted. After a second restart, the message "See Dealer" was displayed with the check engine warning light illuminated. After a third restart, the vehicle was driving rough while the accelerator pedal was depressed. The vehicle was taken to the dealer. The manufacturer was notified of the failure by phone. The failure mileage was approximately 123,000.
On May 24th I was driving back to work form my lunch break, had to make an additional stop before going back and in the moment I was to make a right suddenly the car would not stop or turn, no light were on at the moment, now the car is a total loss and I went trough the scariest time of my life after running into mangroves
This is in regards to a 2021 Toyota Platinum AWD with 8500 miles. While cruising at about 40 miles/hour, the car suddenly lost power, and an alpha numeric code popped on the digital display that said "Chip malfunction" and something else I don't recall. It also said to see your dealer immediately. On the dash, the check engine light came on with a message that said "reduced engine power". This message alternated with another alpha numeric code. I did not write down the actual codes because I thought the car would record them. I was able to roll onto a side street and turn off the car. After 5 min, I restarted the car and took it to the dealer later that day. They not only could not find a code in the record, the entire trip was not recorded, even though it's on my Toyota app. First, they tried to say it couldn't have happened because it was not recorded. …
We have owned our 2021 hybrid awd platinum highlander for 8 months and within the past two months (around 16k miles) it has started to do an acceleration upon applying the brake. The car does catch itself and then after hitting the brake harder it does stop. This has happen on 7 different occasions, flat roads, hills, parking spots now. It has happened while my husband drives it and myself. It was brought it for computer recalls around the same time that this issue started. After the recalls were fixed I brought it back in and left it with the dealer for a few days. They cannot replicate it and therefor won't do anything. They tried to tell me that I can't drive with two feet.... Which I don't. I've seen other reports where Toyota claims it's inexperienced regenerative braking driving. We have owned a 2011 Prius that we had for 6 years and it never did it once. …
We rented this vehicle from Avis at Detroit Metropolitan Airport on Tuesday, 11/22/22 at approx. 7:50 pm. It was raining, cold and temperature was dropping. We drove approx. 1/8 to 1/4 of a mile from the facility. As we turned left on to a major roadway (Goddard) southbound, I turned on the rear defroster. Suddenly, the engine went into limp mode. I tried to make a U-turn to drive back to the facility. Engine lights flashed (low oil pressure, check engine, etc) and then the engine stopped. We barely had enough power to turn the vehicle out of the turn lane before we would have been struck by a bus. We sat in left northbound lane of Goddard for approx. 2 min without our hazard lights on. The vehicle would not start. I then pressed the defroster again and the engine fired up. We drove back to the facility and demanded a new vehicle. …
My 2021 with 73000 miles is now at a dealershop 700 miles away from home. I didn't drive far while away but a week into my vacation, i started hearing a whining sound upon accelerating. Sound seemed to get louder on second day of hearing the sound. Took it to a dealership in the Leesburg Virginia area....they charged me 203.00 for diagnostics and indicated need new transmission for near $11,000. Each time I went to my dealership in my area for an oil change, they indicated that I needed a transmission fluid change. I read that when Toyota installed a "Sealed Transmission System" these changes would not be needed or at least limited.... Because the so call system is sealed, only dealership techs can check your fluid levels. …
Engine complaints in other Highlander years
Frequently asked questions
How common are engine problems on the 2021 Toyota Highlander?
NHTSA has 47 complaints about the engine & cooling of the 2021 Toyota Highlander, 9% of the model year's 531 complaints.
Is there a recall for 2021 Toyota Highlander engine problems?
No. NHTSA lists no engine & cooling recall for the 2021 Toyota Highlander, though it has 4 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2021 Toyota Highlander engine problems start?
Half of the complaints with a recorded mileage happened before about 75,000 miles, and 50% before 25,000 miles.
Is it dangerous?
Owners linked 3 crashes, 2 fires and 2 injuries to engine & cooling problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.