2021 Toyota Highlander: hesitation when accelerating

Filed Oct 9, 2026 · Transmission · 70,100 miles · PA

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at an undisclosed speed, there was a loud high-pitched whining sound coming from the vehicle. The contact stated that the vehicle hesitated while accelerating and the transmission was shifting rough. The contact stated that the vehicle had experienced an internal transmission failure. The manufacturer was notified of the failure. A local dealer was contacted and associated the failure with Toyota Technical Service Bulletin: 0008-21. The contact stated that a diagnostic test was scheduled. The failure mileage was 70,100.

Filed Oct 3, 2026 · Transmission · SC

Transmission jerks and shutters at low speeds on acceleration 0-20 mph. Vehicle has low milage 25518 at which time the dealer re-flashed the software on july 29th 2026.The vehicle was fine for two months , then on October 3rd the problem came back on October 3rd 2026 hesitating like a premature upshift from 1st to 2nd gear at 5 mph with a shutter. The current mileage is 28000 on the vehicle and the problem is intermittent.

Filed Sep 9, 2026 · Transmission · IN

transmission has failed. Toyota states: Toyota Technical Service Bulletin T-SB-0008-21 addresses a whining or grinding noise in select 2021 Toyota vehicles equipped with UA80E orUA80F automatic transmissions caused by a defect in the front carrier assembly pinion shafts. Yes it can be available for inspection. This can be repaired with a $12,000 new transmission. * Sudden loss of acceleration: You may press the gas and the vehicle doesn’t accelerate normally. This is particularly dangerous when merging onto a highway, crossing an intersection, or passing. How this toyota highlander is putting safety at risk: * Unexpected shifting or jerking: A failing transmission can slam into gear, hesitate, or shift unpredictably, potentially causing loss of control. * Loss of drive: The transmission may suddenly stop transferring power to the wheels. You could be unable to move forward even though the engine is running. * Getting stuck in a gear: If it goes into a “limp” or failsafe mode, the vehicle may be restricted to a single gear and have very limited acceleration. * Loss of power while already moving: If the transmission disengages unexpectedly, you can lose the ability to accelerate out of a dangerous situation. * Difficulty maintaining speed: On a highway or uphill, a failing transmission may suddenly stop providing adequate power. * Transmission fluid leaks: A significant leak can cause the transmission to lose lubrication and worsen rapidly. Depending on where fluid goes, it can also create other mechanical problems. * Unexpected engine RPM increases: The engine can rev very high without the Highlander gaining speed (“slipping”), which can leave you unexpectedly slow in traffic. * Being stranded in traffic: A complete failure can leave the vehicle immobile, creating a collision hazard if you’re stopped in a travel lane or on a shoulder. unknown if it has been inspected by anyone. There is no warning lights. Then only way you know is by a high whining sound.

Filed Jun 25, 2026 · Transmission · PA

My 2021 Toyota Highlander is experiencing the documented transmission issue impacting vehicles with the UA80E transmission. Our transmission whines and experiences a hesitation or jerks the vehicle. Especially under acceleration. My vehicle was purchased brand new from Toyota. Serviced at a Toyota dealership since purchase.

Filed May 26, 2026 · Transmission · CA

I own a 2021 Toyota Highlander with approximately 100,500 miles. The vehicle has developed a noticeable whining noise coming from the transmission/drivetrain area that continues to worsen over time. The noise is most noticeable during acceleration and while driving at highway speeds. I brought the vehicle to Toyota for inspection and was informed that the issue is related to the transmission. However, Toyota denied repair assistance because the vehicle is outside the powertrain warranty period. After researching the issue, I discovered multiple similar complaints involving 2021 Toyota Highlanders equipped with the UA80 transmission, including Toyota Technical Service Bulletin T-SB-0008-21 regarding “Whine or Grind Noise From the Transmission.” The symptoms described in the bulletin closely match the symptoms my vehicle is experiencing. Toyota appears aware of this transmission-related issue, yet many owners outside the warranty period are being denied coverage despite similar failures and complaints. I am concerned this may represent a broader transmission defect that could lead to premature transmission failure, unsafe driving conditions, hesitation, loss of power, or expensive repairs for consumers. I believe this issue should be investigated further by the federal safety agency due to the growing number of similar complaints involving whining transmission noises and transmission failures in Toyota Highlander vehicles. At this time, the vehicle has not yet experienced a complete transmission failure, but the condition is worsening and raises significant concerns regarding reliability and safety.

Filed Apr 16, 2026 · Transmission · IL

I am an owner of a 2021 Highlander XLE AWD (bought new). In October of 2024 around 34000 miles the transmission started to make a whining noise and seemed to be surging/bucking , hesitation and hunting for gears. Toyota determined it fit the criteria of a TSB to have the transmission replaced. The dealership had my car for two months and then eventually replaced the transmission with a remanufactured unit. This “new” unit still has the issues of surging/bucking , hesitation and hunting for gears. I fear that this “new” transmission is in the process of failing again with less than 10k on it. Of course I will be out of warranty when it does and I’ll be on the hook for a $10000 repair. I’m appalled that Toyota has not done a true fix for this issue and has not even put an extended warranty on it either. I purchased this vehicle from Toyota on good faith that it would last and be reliable. 34k one transmission died and I’m sure this one will follow suite. Ultimately UA80 transmission is ticking time bomb and Toyota needs to be held accountable for this.

Filed Mar 10, 2026 · Fuel system · PR

*Component/System:** The **Fuel Pump / Fuel Delivery System** failed. The vehicle and the replaced spark plugs/coils are available for inspection upon request. **Safety Risk:** The vehicle **stalls abruptly while in motion (at speed)**, causing an immediate loss of motive power in traffic. This creates an extreme risk of rear-end collisions and leaves the driver stranded in active lanes of travel. The vehicle must be shifted to park, turned off, and restarted to temporarily "reset" the system, which is life-threatening in high-speed or heavy-traffic environments. **Confirmation/Reproduction:** The problem has been confirmed by an **independent service center**. Initial diagnostic codes led to the replacement of spark plugs and ignition coils; however, the stalling persisted. Subsequent diagnostic testing specifically identified the fuel pump as the point of failure, consistent with symptoms of known Toyota fuel pump recalls. **Inspections:** The vehicle has been inspected by an **independent mechanic**. It has not yet been inspected by Toyota corporate, the police, or insurance representatives, as no crash has occurred yet—though the risk is imminent. **Warning Symptoms:** The Check Engine light illuminated on January 21, February 21, Febuary 26, March 6 and March 10. Prior to the first total stall, the vehicle exhibited brief hesitations during acceleration. There were no specific "Fuel Pump" warnings on the dashboard; the vehicle simply loses power without a countdown or secondary safety mode (Limp Mode).

Filed Nov 15, 2025 · Transmission · NJ

Whining sound upon acceleration. Occasional hesitation when shifting gears or rough shifting when going from complete stop to accelerating. Dealership says need new transmission. Warranty company test drove and agreed with dealership findings. 60,000 miles .

Filed Apr 3, 2025 · Engine · PA

TRANSMISSION, Jolts when backing up, and hesitates in traffic. The dealership confirmed it's the transmission. No warning lights, just running poorly with hesitation, afraid of breakdown. First appear a month ago after my warranty expired. I have a 2021 Highlander with 80,000 miles and still owe $22,992.84 on the vehicle. My warranty 60/60,000 is of is not any good. The issues is the transmission. The dealership is telling me it's not covered even though this is an issue with this model. For a another $11,000 they can install a new transmission. Toyota you are better then this, my Camry I had almost 300,000 on it. I had another highlander before this one. Very disappointed.

Filed May 30, 2024 · Brakes · ID

The vehicle hesitates during right turns, creating a hazardous, potentially dangerous, situation. From research I understand this is a known issue when transitioning between battery and gasoline propulsion. Research indicates this is a known situation, Toyota T-SB-0059-23. However, the TSB expires at the termination of the vehicle 3 years/36 months warranty. As a safety issue, in my opinion this problem should be addressed, regardless of vehicle age or mileage.

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.