2021 Toyota Highlander Driver assistance Problems

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.

NHTSA ID

11746525

Incident

Jun 25, 2026

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.

NHTSA ID

11743384

Incident

Apr 25, 2026

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.

NHTSA ID

11738736

Incident

Feb 1, 2026

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.

NHTSA ID

11728216

Incident

Feb 27, 2026

- The vehicle has been experiencing shifting issues (its an automatic vehicle) when driving in all instances and at all speeds that has progressively gotten worse over the past 4-8 weeks. - As it seems to be a transmission issue (and a known one pending litigation) the safety issue is if the transmission fails during operation of the car. - It was brought to a dealership to be inspected after it was initially felt as more of a vibration than the more harsh shifting/engine sounds and issues that it is currently experiencing. The dealership thought it to be the front hub assembly/bearing that was the issue. I had the front driver side replaced and the issue still remains and has continued to worsen. It has not been inspected by the manufacturer, police, or insurance representative. - There have been no warning lamps or messages at all. - Through research it appears this is a known issue with ongoing litigation (2 class action lawsuits currently in litigation related to UA80F transmissions of which it appears that our VIN is in the affected group).

NHTSA ID

11713495

Incident

Jan 26, 2026

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the vehicle jerked abnormally and failed to accelerate as intended while depressing the accelerator pedal. The contact pulled to the side of the road. The vehicle failed, then failed to respond while in drive or reverse. No warning light was illuminated. The contact called for Roadside Assistance and had the vehicle towed to a safe location. The vehicle was then towed to an independent mechanic, who diagnosed the vehicle and informed the contact that the transmission had failed and needed to be replaced. The vehicle was not repaired due to the cost. The manufacturer was not notified of the failure. The failure mileage was unknown.

NHTSA ID

11712736

Incident

Jan 9, 2026

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.

NHTSA ID

11649388

Incident

Feb 10, 2025

Mileage

45,000 mi

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. 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 NHTSA to investigate and take action to protect consumers from unfair repair costs and potential safety risks.

NHTSA ID

11639473

Incident

Jan 29, 2025

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

NHTSA ID

11626440

Incident

Aug 19, 2024

Unknown

NHTSA ID

11608965

Incident

Jul 26, 2024

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.

NHTSA ID

11606573

Incident

Aug 4, 2024

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.

NHTSA ID

11604891

Incident

Oct 4, 2023

While accelerating onto the freeway the vehicle suddenly loses power creating a serious safety issue. A check-engine light comes on but the safefy issue is that the vehicle goes into a power loss mode ON THE FREEWAY. A truck nearly rear-ended me the first time it happened. Toyota Service was unable to duplicate and so said National Toyota advised them to release the vehicle back to me. The same issue happened to my boyfriend and his son - total loss of power while accelerating onto the freeway. Then a mechanic recreated the issue 5 additional times (usually in the dawn hours when traffic was light due to safety concerns). Was unable to find the cause of the issue but a loss of power in a vehicle is as serious a concern as an unwanted acceleration. I am frustrated that Toyota is not taking this seriously.

NHTSA ID

11589082

Incident

Apr 17, 2024

While depressing the brake pedal the vehicle continues to accelerate before finally slowing to a stop. This happens on bumpy road surfaces as well as level road surfaces. There were no warning lights, alarms or messages prior to or during the failure. This issue started around 35,000 mileage and has progressively gotten worse to current day. (Current mileage as of 1/29/2024 is 54,346.) This issue would cause the vehicle to potentially rear end a vehicle you are following or propel the vehicle into an intersection typically controlled by a traffic signal or device. Local dealer has said there is nothing wrong as they could not replicate the issue.

NHTSA ID

11568711

Incident

Jan 29, 2024

Varias veces mientras conduzco en la ruta la velocidad permitida, el carro frena, pierde potencia el motor, el sistema de aceleración no responde, esas veces me salve de accidentes mortales junto a mi familia, reclame a toyota corporación indicar eso y para ellos no paso nada nunca tomaron en serio, mientras que el carro para reparar eso, paso más de 25 días en las veces que se daño xq prácticamente el carro no es seguro para manejar

NHTSA ID

11563517

Incident

Feb 2, 2022

The steering technology in this vehicle reads lines on the road that are not correct or valid lanes and almost caused several accidents during the 2 years I had the vehicle. Luckily, I was paying attention and had to jerk the wheel to the correct lane but the steering wheel will force itself to the other false lane. This is extremely dangerous and this is a huge safety issue.

NHTSA ID

11552496

Incident

Oct 29, 2023

The lane assist will not stay turned off, even when it is done manually each time I get in the car. The steering pulls me back when I'm trying to change lanes, making it unsafe.

NHTSA ID

11552162

Incident

Oct 5, 2023

I was driving 50 mph on 28 E in Pineville, Louisiana when I heard what sound like a gunshot. I pulled over and realized my sunroof exploded.

NHTSA ID

11525473

Incident

Jun 5, 2023

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.

NHTSA ID

11509671

Incident

Apr 1, 2021

Mileage

12,000 mi

my car experiences intermittent acceleration when applying the breaks. It lunges forward for some reason. It has also not stopped when hitting the breaks hard but lunges as well. I am using the last date that this happened.

NHTSA ID

11508626

Incident

Feb 20, 2023

Warning lights appeared while driving on city streets.

NHTSA ID

11507424

Incident

Jan 23, 2023

Unwanted acceleration happen more the 5 to 6 times. While driving in highway exit ramp my vehicle lurched forward while I was trying to slowdown. Dealership had the vehicle for more than 2 days and unable to duplicate the issue. Currently Toyota dealership informed they don't any know issues or condition like this. I am not very confident in driving this vehicle due to this experience.

NHTSA ID

11506579

Incident

Feb 8, 2023

Forward Collision Warning and Automatic Emergency Braking isn't functioning as stated in the Toyota Highlander 2021 Owner's Manual. Dealer stated that software tests were conducted and the vehicle's radar and optical sensors are performing in accordance with the test results. However, there is only intermittent warning lights and alarms that are functioning. The dashboard audio and visual alarms only function in rare encounters on approaching a vehicle. The service manager rode with me and when I was approaching a vehicle where an alarm should have sounded or illuminated inside the vehicle, that did not occur. However, the software tests showed that the vehicle was approaching on a collision event that was recorded on the system, but failed to alert the driver. After additional testing, the service manager stated that the vehicle reads stop lights from the vehicle ahead to execute the safety functions of the forward collision warning and automatic emergency braking safety feature. The Owner's Manual doesn't make that claim. In addition, another service manager stated that the system uses artificial intelligence to learn the driver' habits and the system adapts to the driver. The Owner's manual doesn't state that claim either. Lastly, the invoice stated that the owner should read pages 257 and 260 of the Owner's Manual to understand how the system operates. This describes the Dynamic Radar Cruise Control functions and not the Forward Collision Warning or Automatic Braking functions. This information is found on pages 235-238. They missed the problem. My suggestion was that their test only looked at a single variable that may have covered the external sensor operation and didn't test the dashboard internal warning system of the audio/visual alerts inside the vehicle. My recommendation was to seek assistance from the supplier that manufactured this system and seek guidance from their engineering staff. I complained to the Toyota Corporate Customer Servi

NHTSA ID

11469290

Incident

Sep 12, 2021

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.

NHTSA ID

11466817

Incident

Apr 27, 2022

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.

NHTSA ID

11444627

Incident

Aug 20, 2021