2021 Toyota Highlander: sudden unintended acceleration

Filed Dec 16, 2025 · Brakes · MA

I own a 2021 Toyota Highlander Hybrid. The vehicle exhibits a dangerous braking surge defect. When braking during cornering or in stop-and-go traffic, the vehicle randomly surges forward even though the brake pedal is depressed. This creates a serious safety hazard and increases the risk of collision. On multiple occasions, this defect has nearly caused an accident. The last time it happened we were driving in stop and go traffic and the vehicle surged forward while depressing the brakes and the engine died leaving a red triangle on the dash. Toyota has acknowledged this condition through Technical Service Bulletin T-SB-0059-23, which applies to my vehicle. The bulletin involves reprogramming the brake actuator assembly control module to address the braking transition between regenerative and hydraulic braking. Despite this, Toyota has refused to apply hybrid system warranty coverage, misclassifying the defect as a conventional brake issue. My vehicle is available for an inspection. I contacted Toyota corporate, who initially responded but failed to provide follow-up or resolution. The defect persists after the bulletin was applied. Toyota’s refusal to cover the repair under the hybrid warranty leaves me with an unresolved safety defect. This complaint is intended to document the ongoing safety risk and Toyota’s failure to provide adequate remedy under warranty. I request the federal safety agency investigate this issue as a systemic safety defect affecting 2020–2022 Highlander Hybrid models.

Filed Nov 2, 2023 · Brakes · IN

While slowing and braking to stops (approximately less than 20 mph), the vehicle will lurch/lunge forward. It feels like you took your foot off the brake pedal but you did not. This occurs randomly. It does not happen every time. There are no warning lamps, messages, etc., prior to or during this issue. The vehicle has ~39000 miles. This has been occurring for at least 20000 miles. Risk: If this occurs when close to pedestrians, other vehicles, intersections, etc., it could result in an impact. The dealer could not reproduce but did find online message forums that reported the same issue.

Filed Jun 11, 2023 · Brakes · IL

When braking, often it feels like the brakes are not engaged, not right away, but during the braking process. This causes the vehicle to surge forward like there are no brakes. Immediately you feel like the brakes failed, then you push them again, they work. It is very random with no reference to different speeds, inclines, never know when it may happen. It has caused many near misses for our family whenever this happens.

Filed Mar 1, 2023 · Acceleration · 12,000 miles · MD

The contact owns a 2021 Toyota Highlander. The contact stated that while driving approximately 3 MPH, the brake pedal was depressed; however, the vehicle surged over the curb and sidewalk. The contact was able to release the brake pedal, stopped the vehicle, reversed, and parked the vehicle. While driving on a hill with the accelerator pedal depressed, the vehicle hesitated and failed to properly drive forward. The vehicle was taken to the local dealer who was unable to duplicate the failure. The vehicle was not diagnosed or repaired. The vehicle was taken to another local dealer, Germain Toyota of Naples (13315 Tamiami Trail N, Naples, FL 34110), who informed the contact about a brake issue and provided an unintended acceleration form; but the vehicle was not diagnosed or repaired. The vehicle was taken back to the original dealer who informed her about brake calibration. The vehicle was not diagnosed or repaired. Additionally, the tailgate failed to open, and the seat heaters became inoperable. The remote start failed to turn off. The windshield wipers randomly came on for five minutes but self-corrected. The manufacturer was contacted but provided no additional assistance. The failure mileage was approximately 12,000.

Filed Jun 22, 2021 · CA

I purchased my Toyota Highlander Hybrid only about 2 months ago. Since then, I've experienced several incidences of sudden acceleration. In a few of them, I was approaching a stop sign and began to slow down. Suddenly, I felt the car accelerate on its own. In both instances, I slammed on the brakes and the car jerked then stopped. There was one instance when I was going down hill and I was stepping on the brakes, but the car seemed to accelerate on its own until I stepped on the brakes again. Fortunately, there were no collisions. However, this is a serious safety problem.