Table 1 shows one common vehicle speed control related problems of the 2020 Toyota Highlander.
| Problem Category | Number of Problems |
|---|---|
| Vehicle Speed Control problems |
Vehicle: 2020 Toyota Highlander xle purchased: August 2020 owner: original owner transmission: ua80f dealer quote for “transmission assembly remove and replace: $8,666. 22 +tax the vehicle is experiencing delayed acceleration (lagging power) and a loud whirring noise from the transmission when the accelerator pedal is pressed. The whirring noise immediately stops when the accelerator pedal is released. The Toyota Highlander had just exceeded the 60,000 mile/5 year powertrain warranty. Vehicle has 68,079 miles and is 5 1/2 years old. The delayed acceleration creates a serious safety hazard, particularly when starting from a complete stop while attempting to make a turn into traffic. On multiple occasions, the vehicle failed to respond promptly when the accelerator was pressed, placing the vehicle at risk of being struck by oncoming traffic. On February 17, 2026, oakbrook Toyota diagnosed the vehicle with a failed/bad transmission after charging a $200 diagnostic fee to investigate the whirring noise and power delay. This failure occurred on a vehicle that has been properly maintained and has not been modified. Upon searching the internet, there are many, many complaints regarding the ua80 transmissions failing between 60,000 and 70,000 miles. There are also multiple lawsuits filed for failed transmissions.
At approximately 120,000 miles, the vehicle began exhibiting a pronounced shudder or vibration between 40–50 mph under light acceleration or steady cruising. The condition progressed to delayed shifting and intermittent loss of acceleration response. The most concerning issue is hesitation and reduced acceleration when attempting to merge into traffic or increase speed. On multiple occasions, the vehicle failed to respond promptly to throttle input, creating a potential safety hazard due to loss of propulsion. The vehicle was evaluated at two authorized Toyota dealerships. Both indicated that the condition is consistent with torque converter or transmission failure. Full transmission replacement was recommended at an estimated cost of approximately $9,000. No whining or grinding noises are present; symptoms primarily involve shuddering and hesitation. The vehicle has not been driven since October 21, 2025, due to safety concerns and to prevent further damage. The vehicle has been regularly maintained at Toyota dealerships and has not been used for towing. This complaint concerns loss of acceleration, transmission shudder, and potential premature failure of the 8-speed automatic transmission.
My wife was pulling into a driveway slowly approximately 5 mph when she went to stop the Toyota Highlander sped up to full speed and smash the tree while my wife was depressing the brake. All airbags were deployed and it looks like they are going to total the Toyota Highlander that has all the maintenance records very lucky to not have somebody seriously injured.
The contact owns a 2020 Toyota Highlander. The contact stated that there was an abnormal winding noise detected while accelerating. The failure increased over time. While her husband was driving at approximately 60 mph attempting to accelerate, the vehicle lost motive power. While shifting to park, there was an abnormally loud, high-pitched winding sound detected. The vehicle was slow to shift from first to second gear. There were no warning lights illuminated. The vehicle was taken to an independent mechanic, who determined the cv joint needed to be replaced. The vehicle was repaired, but the failure recurred. The vehicle was taken to a transmission center, where the transmission was rebuilt and then it was replaced. The contact called the local dealer, but the vehicle was not diagnosed or repaired. The manufacturer was not contacted. The approximate failure mileage was 130,000.
I was pulling into a parking space in a parking garage. As I was pulling in, the car unintentionally had a rapid acceleration event and crashed into a cement pillar causing the car to be a total loss.
When coming to a stop the vehicle will often lurch forward. The lurch is powerful and could easily cause a collision. This problem occurs both when stopping in traffic and pulling into parking spaces. We were told by the dealer that the problem is caused by hybrid cars but we've had hybrid cars before that did not exhibit this behavior. It sounds like the dealership is aware of the problem but Toyota is not addressing it. This issue certainly poses a safety issue, especially for vehicles in front of the affected vehicle when attempting to stop.
The contact owns a 2020 Toyota Highlander. The contact stated that after slowing down to come to a stop, the vehicle would inadvertently surged forward. There were no warning lights illuminated. The vehicle was taken to the dealer who was unable to determine the cause of the failure. The vehicle had not been repaired. The failure had since become more frequent. The manufacturer was made aware of the failure. The approximate failure mileage is 36,009.
Vehicle went into limp mode reieved code p0300 reduced engine power on highway when accelerating.
Driving 50 miles/ hour veh�cle started loosing power and started to shake. Engine light came on and two different messages in dashboard pop out. One about hybrid malfunction and the other output power reduced.
We recently purchased our Highlander and it has a little over 4,000 miles. Today while driving down the road at about 45 mph, the car just lost power and the check engine light came on. 1. Check engine - reduced engine power 2. Secondary collision brake system malfunction we had to park and wait for the Toyota dealership to come and tow it to the service center. At this point I don't know what was wrong or why it just cut out while driving. I am very concerned and can only hope Toyota can address this or replace the car.