Which parts fail
Components named in complaints (automatic emergency braking, adaptive cruise, lane keeping, backup camera).
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 while driving 60 MPH, the vehicle inadvertently attempted to navigate the steering and lane direction to the opposite direction of where the contact was attempting to steer the vehicle. This caused the contact to manually steer the vehicle into the center lane. There were no warning lights illuminated. The contact took the vehicle to a local dealer who inspected the vehicle but could not diagnose the cause of failure. The dealer informed the contact that the vehicle lane sensor and steering assist sensor were performing as intended. The contact was concerned that the sensor should be adjusted so that the sensor would not have to adjust so easily while the contact was driving. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 5,000.
The contact owns a 2021 Toyota Highlander. The contact stated that while operating the vehicle, the display screen malfunctioned and displayed a solid black screen. During the failure, several functions and features could not be accessed or activated, including the front and rear defrosters. The contact was unable to clear the front and rear windshields, which created a visibility hazard for the driver. The vehicle was taken to the local dealer, who diagnosed that the display screen unit needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 45,000.
The Forward Collision did not activate cause the vehicle to meet into a accident. the car didn't give a Warning, or try to stop itself. took it to the dealer and was told that the system was working properly. but I tested the system in the parking lot, with a cardboard box and the system still didn't activate.
Subject: Transmission Issue - 2021 Toyota Highlander Dear NHTSA, I am reporting a serious transmission issue with my 2021 Toyota Highlander (82,000 miles). I recently took it to the dealership for an unusual noise, and they diagnosed a transmission failure, quoting over $9,000 for replacement and service. After researching, I discovered Toyota has known about transmission issues in the 2021 Highlander since at least 2021. I have always serviced my vehicle at the same dealership, yet they never informed me of this known defect. Instead, they waited until my warranty expired to disclose the issue, despite my repeated maintenance visits where I reported the noise. I also found a 2021 Toyota document acknowledging transmission problems in this model, and many other owners have reported the same issue. …
I consider this a vehicle safety issue. Was on the freeway, center lane of a 3 lane highway. The vehicle to my left began to move into my lane. I had to quickly move to my right, activating my lane departure and steering assist. This caused my vehicle to attempt to move me back into my lane (where the other driver was now trying to occupy!). I was shown how to disable this feature if desired but what I wasn't told by the dealer, is that this feature can no longer be set to default to off. I just finished a lease of a 2018 Toyota Rav4 which also had this feature but once I disabled it, it was disabled unless I re-enabled it. With this new vehicle, when you disable this feature, it's only disabled until you turn off the vehicle. When the vehicle is turned on again, this feature is set back to active. …
The vehicle experiences intermittent power steering malfunction while driving. Warning messages including "Power Steering Malfunction" and "Low Voltage Abnormality" appear, and the steering wheel becomes stiff and difficult to turn. This has occurred multiple times during normal driving conditions, including at low speeds and while turning. When the issue occurs, it requires increased effort to steer, creating a risk of loss of control. Additional warning messages have included AWD malfunction, pre-collision system malfunction, and lane tracing assist malfunction. These alerts appear simultaneously with the steering issue. The problem began shortly after purchase and has continued intermittently. The vehicle has been inspected, but the issue has not been resolved. This condition creates a safety risk, especially when driving with passengers.
The start/stop operating system failed. When the engine cut off while waiting for train to pass, the engine went to turn over and completely stopped the vehile. Although the car would not start, I was unable to cut the car off completely. It would say ignition on. The lights in vehicle were on. Running the ac caused the car to say high power consumption but there was no way to cut vehicle off without removing the battery to reset the vehicle. Caused the car to malfunction while sitting at a complete stop. Also cause the parking break to engage and I was unable to disengage parking break. A message came across saying parking break unavailable. My safety and others were put at risk because had it happened at any other time a crash would have been caused. It caused a roadway to be blocked off which caused confusion and near accidents.
The rear cross traffic avoidance does not detect a person on a bicycle or motorcycle. The safety sense 2.5 + was advertised and demoed to detect even a pedestrian walking behind the vehicle. The system on my vehicle does not work as advertised and after taking my vehicle to the Dealer was informed by the service manager that the system is "intermittent at best". This is not what Toyota advertises. Dealerships apparently have no signal strength detection equipment to verify proper operation of this system. I have reviewed multiple videos of this system in operation and there were no indications of intermittent failures. I have contacted Toyota Customer support and am being ignored.
The electric park brake makes a loud screaming sound during engaging cycle as I put the gear in park. The sound gets worse during warmer weather. I visited the dealer twice for the same problem and reported it to Toyota. During my visit another highlander came into dealership. It made the same sound when the driver placed it in Park. According to the dealer, this sound is normal. I say it's not. I have way cheaper cars with Electric park and they don't make this sound. If the park brake unit fails it's going to be real costly to repair and may fail while driving and gets engaged.
2021 Toyota Highlander UA80 transmission failed at 100,000 miles. Codes P2808, P0741. Matches Toyota TSB-0160-18 and T-SB-0008-21. Dealer Alexander Toyota and TMS Brand Engagement denied goodwill. TMS rep stated "TSBs don't matter" despite pending class action Pallaya v Toyota, Case 2:25-cv-10458, which cites these TSBs as proof Toyota knew of defect. Toyota refusing to honor documented defect. Transmission slip/loss of power is safety issue. Request investigation.
Collision Avoidance complaints in other Highlander years
Frequently asked questions
How common are collision avoidance problems on the 2021 Toyota Highlander?
NHTSA has 21 complaints about the driver assistance of the 2021 Toyota Highlander, 4% of the model year's 531 complaints. The component named most often is automatic emergency braking (9 mentions).
Is there a recall for 2021 Toyota Highlander collision avoidance problems?
No. NHTSA lists no driver assistance 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 collision avoidance problems start?
Half of the complaints with a recorded mileage happened before about 5,000 miles, and 67% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 1 injury to driver assistance 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.