2021 Toyota Highlander driver assistance problems

Filed Jun 25, 2026 · Driver assistance · AZ

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.

Filed Jun 11, 2026 · Airbags, Driver assistance · NC

Four days after I took delivery of this used vehicle (April 25, 2026), multiple warning lights appeared at once: BRAKE, ABS, PARK, Check Engine, Blind Spot Monitor Unavailable, and RCTA OFF. An independent Toyota dealership diagnosed the vehicle April 27-28, 2026 (approx. 109,000 miles) and found (1) water leaking into the rear hybrid battery area through a sunroof drain "installed incorrectly," causing a Brake System Control Module low-voltage code, starting issues, a headlight only partially functioning on one side, possible air in the brake system, and a musty HVAC odor; and (2) blind spot monitor fault code C1AC2 (Slave Module Horizontal Axis Misalignment) - the blind spot and rear cross-traffic monitoring systems do not function reliably. At a second visit on May 4, 2026, recalibration was unsuccessful; per Toyota procedure the only remaining option is replacing the right-rear blind spot sensor. The technician wrote the cause is a mystery, "whether it be body damage related or electrical short." Toyota service records show the same C1AC2 code was documented during the selling dealer's own pre-sale inspection, and that in December 2024 another Toyota dealership pulled the rear bumper and found the RR blind spot sensor bracket bent, causing incorrect readings - a recurring safety defect that prior calibrations and repairs have not resolved. Separately, federal safety recall 23V865 (occupant classification sensors; the passenger airbag may not deploy as designed) was open and incomplete when I purchased the vehicle and remains incomplete, and Toyota service campaign 25TD01 (rear traction motor cable corrosion) is also outstanding. The defect has been reproduced and confirmed by two Toyota dealerships, reported to the selling dealer in writing, and reported to Toyota's customer-care center. The vehicle is available for inspection upon request. No crash, fire, or injury.

Filed May 19, 2026 · Driver assistance · VA

The parking sensor bracket has failed twice now and the sensor keeps falling through. There are no signs of scratches or bumps on the bumper. The dealer said that’s not something they will fix. I have had it fixed once before and now it’s happening again.

Filed Mar 31, 2026 · Driver assistance, Electrical · FL

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.

Filed Mar 20, 2025 · Driver assistance, Visibility · 45,000 miles · NH

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.

Filed Jan 29, 2025 · Driver assistance · NJ

Subject: Transmission Issue – 2021 Toyota Highlander 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. It seems dealerships avoided addressing this until warranties expired, leaving owners with massive repair costs. This raises serious concerns about Toyota’s handling of known defects. I urge the federal safety agency to investigate and take action to protect consumers from unfair repair costs and potential safety risks.

Filed Nov 20, 2024 · Driver assistance, Electrical · CA

The Battery was leaking fluid, smoke was visible and rotten smell from the battery. Electrical secondary brake system came on the dashboard

Filed Aug 16, 2024 · Airbags, Driver assistance · AZ · crash · 1 injury

Unknown

Filed Aug 5, 2024 · Driver assistance, Electrical · TX

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.

Filed Jul 27, 2024 · Brakes, Driver assistance · MI

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.