2024 Toyota Grand Highlander

While driving my 2024 Toyota Grand Highlander Hybrid AWD at highway speed with only 16,755 miles on the vehicle, multiple warning messages suddenly appeared, including warnings related to the engine, hybrid system, AWD system, and other vehicle functions. The vehicle instructed me to pull over immediately and significantly reduced power output, making it difficult to maintain highway speed and safely maneuver through traffic. I was able to reach the shoulder and had the vehicle towed to a Toyota dealership. The dealer diagnosed a punctured radiator caused by a rock or similar road debris that allegedly passed through the front grille and struck the radiator. The dealer confirmed that coolant loss from the puncture triggered the vehicle's protective reduced-power mode. This failure created a significant safety risk. A sudden loss of power while traveling at highway speed increases the risk of rear-end collisions and other accidents, particularly in heavy traffic where drivers may not expect a vehicle to rapidly decelerate. There were no warning lights, messages, leaks, drivability concerns, or other symptoms before the incident. All warnings appeared suddenly at the time of failure. Toyota has declined warranty coverage, classifying the damage as a road hazard. However, I believe this may indicate a design defect. I have identified numerous reports from other GH owners describing nearly identical failures involving rocks penetrating the radiator through the front grille, often at relatively low mileage. These reports suggest the radiator may be inadequately protected from ordinary roadway debris. My concern is not simply radiator damage, but that a small piece of road debris encountered during normal driving can disable a critical component and cause the vehicle to enter a severe reduced-power mode at highway speed. I request that NHTSA investigate whether the front grille and radiator protection design of the Grand Highlander creates an unreasonable safety risk

The incidents most often occur when I try to accelerate after vehicle is stopped at an intersection. The car hesitates during acceleration regardless of how much I push the gas. Once it starts to go, it feels as though the car can't shift from 1st to 2nd gear. The RPMs get up 4500 while the car is going 25-40 mph and remain there for a few seconds up to ~20 seconds. I am fearful of getting t-boned when my car hesitates while turning at an intersection, going through an intersection or pulling out from a parking lot. I have been stuck in several intersections when traffic was coming toward me, but thankfully those cars were able to avoid hitting me. I have reported the problem every time I take the car to the dealer for a service. The problem has been happening since I purchased the car in November 2024 and occurs randomly--sometimes every couple of months, sometimes days in a row. The dealer can't reproduce it, but they were able to pull a code from the transmission and found it had an acceleration error. They updated the software from a TSB, but that didn't help.

I am submitting this complaint regarding a catalytic converter failure on my vehicle and the manufacturer’s refusal to honor the warranty. My vehicle is a Toyota that is approximately two years old and currently has about 31,000 miles. The catalytic converter has failed well before what would normally be expected for this component. When I brought the vehicle to the dealership for repair under warranty, Toyota declined to cover the repair. They stated the failure was due to “contaminated fuel,” but they did not provide any evidence or test results showing that contaminated fuel was present in the vehicle. I have not been provided with documentation, diagnostic data, or fuel analysis supporting this claim. The denial appears to be based on assumption rather than proof. Because catalytic converters are emissions components that are typically expected to last much longer and are often covered by extended emissions warranties, I am concerned this may represent a broader issue affecting consumers. Vehicle details and service documentation can be provided upon request. I am requesting that this matter be reviewed and that the manufacturer be required to provide evidence supporting their claim or honor the warranty repair. Thank you for your time and consideration.

Description of Issue: We have experienced multiple episodes of violent shaking in our 2024 Toyota Grand Highlander while stopped at red lights or in intersections. Both my wife and I have had this happen independently, around two to three times each. Most incidents occurred while our young children were in the vehicle. The most recent incident occurred today, when my wife experienced it twice in a row while stopped at an intersection. Our children were not in the vehicle during today’s event. Component or system involved: UNKNOWN at this time. We suspect a major mechanical or drivetrain-related failure. The entire vehicle shakes violently and feels unstable. We are willing to make the vehicle available for inspection upon request. Safety risk: The severity of the shaking is extreme and it feels as though the car may explode or fall apart. We have had to put the car in park, shut it off immediately, and in some cases, exit the vehicle in the middle of intersections or while stopped at a red light. This places everyone in the vehicle at serious risk, especially our children, and could result in a crash or secondary accident due to the abrupt stop and unexpected behavior in active traffic. Has the problem been reproduced or confirmed by a dealer or service center? The issue has not yet been reproduced by the dealership. We brought the vehicle to Toyota of Escondido after a previous incident. They inspected it but stated they could not find anything wrong. Has the vehicle or component been inspected by others? The vehicle was only inspected by the dealership (Toyota of Escondido). It has not been reviewed by any other parties such as law enforcement or insurance representatives. Warning lamps, messages, or other symptoms prior to the issue: There were no warning lights, error messages, or abnormal behavior prior to the onset of the violent shaking. The issue occurred suddenly each time, without warning.

Ever since I got my car, sometimes it smells like gas on the right side of the vehicle. By driver side and right passenger side in the back. I assumed it was because I topped my gas off, but even when I stopped doing that, it still has a strong gas smell when the car is running and after turning it off. Not ever day, but ever so often.

Shortly after starting my vehicle and driving out of my neighborhood, there are a series of stop signs. The roadway is at a slight incline. When attempting to press the gas pedal after stopping at the first stop sign, my vehicle hesitates or does not accelerate. This lasts anywhere from 1-5 seconds. This occasionally also occurs again at the second stop sign a few hundred yards later as well. The best I can describe this is as an unresponsive gas pedal or limp mode. I cannot stress how incredibly dangerous this issue is. Someone is going to get seriously injured or killed if this isn’t acknowledged by Toyota or NHTSA. All it takes is for this to occur when someone is making a right hand turn into a roadway. I am fully aware that this is not an isolated incident with my vehicle and other vehicle owners of Toyota Hybrid Max Platinums report this same issue.

Intermittently, my vehicle will hesitate to accelerate or will move only marginally (disproportionately to the depressing of the gas pedal) from a complete stop. When it occurs, it often does so for a number of seconds. This has been incredibly dangerous given I live off a busy street and I cannot trust that when I press the gas pedal to accelerate to turn onto the street, that my vehicle will be caught in oncoming traffic and hit.

After driving over 15k miles in approximately one year, my 2024 Toyota Grand Highlander Hybrid fuel tank has never been filled with more than 12 gallons of gas, even when the Low Fuel light is on and the miles to empty are less than 10. The MPG for individual trips can be as low as 10.3 MPG; the overall average MPG has been 21 MPG or less. The advertised fuel tank size is 17 gallons and the MPG is 26/27. The Toyota dealership said that there are 3-5 gallons remaining in the tank when there are as few as 5 miles to empty. Actual miles to a tank are around 280-300 when driven in Eco mode; advertised is 450 miles when driven normally. Inaccurate fuel level sensing is a safety issue. 10.3 MPG for a Hybrid that is advertised to get 27 MPG is false advertising. This is a known issue since at least November 2023, as evidenced by the Manufacturer Communication Tech Tip T-TT-0742-23 on NHTSA.GOV.

Since we purchased the 2024 Grand Highlander Hybrid Limited in April 2024, there has been an issue filling the fuel tank completely when the vehicle is on empty. The stated fuel tank capacity from the owner’s manual is 17.8 gal, however the maximum amount of fuel that can be pumped into the tank using auto fill at the gas station is 12 gal before the pump “kicks off”. After this, the fuel gauge on the dash reads full, however fuel range shown is 330 mi (at 30 mpg average gas mileage) when it should be closer to 500 mi with specified fuel tank capacity of 17 gal and 30 mpg. Shortly after filling the fuel tank, the fuel gauge and range will quickly decrease while driving. From researching and reading dozens of online forums about this issue, I tested filling the tank manually at the pump, extremely slowly, not using the auto fill lever. Two times doing this test, I was able to pump 14.5 gal into the tank before the pump “kicked off”. After these fill ups, the fuel gauge showed full and did not quickly decrease when driving. Also, the range now showed 450+ mi remaining. Both times after what appears to be an actual full tank fill up, the vehicle recorded over 400 miles before the fuel low light turned on, while previous max miles was in 300 range. It seems as if the fuel tank design does not allow the fuel to enter and settle in the tank quickly enough when filling, causing the pump to “kick off” prematurely and not actually fill up the tank. This issue causes the vehicle to not reach the full mileage range with advertised MPG and tank capacity, causing more frequent and inconvenient trips to the gas station. We have taken the vehicle to a Toyota Service center and they documented the issue but were told by Toyota Corporate that they do not have a fix for it at this time. Tech Tip T-TT-0742-23 exists on NHTSA.GOV website related to this issue from November 2023.