2024 Toyota Grand Highlander

Vehicle: 2024 Toyota Grand Highlander Hybrid Max The vehicle intermittently experiences a severe hesitation and shudder during acceleration from approximately 0-40 mph. The condition occurs only under specific circumstances: -The vehicle has been parked long enough for the engine, transmission, and related systems to cool to ambient air temperature. -The vehicle is started and driven shortly thereafter. -Engine oil and transmission temperatures are below approximately 160°F. -The air conditioning system is operating at maximum cooling with Eco Air Mode enabled. -The hybrid battery indicator displays approximately three bars of charge. When these precise conditions are present, the vehicle may hesitate, shudder, and fail to respond normally to accelerator pedal input during acceleration. Even with the accelerator pedal fully depressed, repeatedly, there is a noticeable delay in power delivery and vehicle acceleration. This creates a situation where the vehicle does not accelerate as expected when entering traffic or attempting to increase speed. The vehicle has previously received Toyota Technical Service Bulletin T-SB-0017-24; however, the condition continues to occur intermittently. No warning lights, diagnostic messages, or system faults are displayed when the event occurs. The condition typically occurs only once during the initial drive cycle after a cold start and has not been observed after the vehicle reaches normal operating temperature. The issue is most common in the warmer months and has never been encountered at freezing or below temperatures.

A couple of days ago, I was driving when my Toyota Grand Highlander started displaying a series of alerts. These alerts included "Hybrid system malfunction" "All Wheel Drive malfunction," "Check engine. See dealer," and finally something akin to "Find a safe place to pull over and turn off vehicle." Until these alerts appeared, back-to-back-to-back, there were no indications that there was anything wrong with the car. We were fortunate enough to be both close to home and close to a dealership when this happened and were able to bring the car in right away. If we were in a high traffic situation, or, conversely, in a very rural area (specifically in winter, not an unlikely happening for us), having the car's drive system suddenly fail out of nowhere could have been very dangerous. As I said, we were able to get the car to the dealer soon after. The dealership informed us that the car has a coolant system perforation, more than likely from a rock penetrating the grill. The coolant than leaked, causing the hybrid system/other failures the car noted. I have since done some research on this issue and have found, to my dismay and disappointment, that this isn't an uncommon issue with the Grand Highlander and the Highlander. There are many instances of people on social media saying a similar issue happened with their cars - one other person's dealership quoted them the exact same amount of the repair that our dealership did. In fact, this is such a common issue that there is apparently already an established workaround: other owners have ordered aluminum mesh from third party vendors and have zip-tied it to their grills in order to keep the rocks out. This is an absurd thing to have to do. Consumers should not, in the year 2026, have to drive down the road with concern that a loose pebble will put their car out of commission. Cars should be able to withstand this very common occurrence without taking substantial damage. This seems like a design flaw.

The vehicle hesitates and does not accelerate immediately from a complete stop. This occurs more frequently when the car is on a slight incline. The delay in acceleration creates a safety concern, especially when attempting to merge into traffic or pull out onto a roadway. I have reported this issue to the dealership multiple times, but they have not taken action because they have been unable to reproduce the problem.

I was driving toward the perimeter of my neighborhood, approaching an arterial cross street. When I braked the pedal went straight to the floor. The breaks didn’t work despite pumping them multiple times. I also heard the engine revving. To avoid the intersection and busy street I steered into a yard, hit a retaining wall and a tree, rolled and hit a metal city street sign. All airbags deployed. I was taken to the hospital by ambulance. The car was totaled and is on a temporary hold at a salvage yard.

The transmission needs to be replaced per the dealership. I was told this on 3/7/26 with mileage of 69K. The transmission has been reported as defective to Toyota since 2016-2017 with multiple lawsuits that have been filed. According to the lawsuits found online, Toyota knowingly used the defective UA80 transmissions and failed to inform consumers when purchasing the vehicles or inform consumers the need to replace prior to the 60k warranty expiration. The 2024 Grand Highlander has been listed as one of the affected vehicles and the transmission can fail at any time which is a 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.

Reported issues of lag in acceleration and harsh shifting into reverse, the vehicle has been brought to the dealership multiple times stemming from shortly after previous, there are no warnings lights on. I requested the dealership provide in writing if the deemed the vehicle safe for operation. They would not do so. I requested a loaner while my vehicle is being reviewed for repurchase and was denied. When my repurchase claim was denied, I requested a reconsideration and again a loaner.

The contact owns a 2024 Toyota Grand Highlander. The contact received notification of NHTSA Campaign Number: 25V595000 (Electrical System), and the vehicle was taken to the dealer on several occasions, but the dealer informed the contact that the part to do the recall repair was not yet available. The contact stated that the instrument panel had failed. Additionally, the contact stated that the vehicle was not driving properly, and the vehicle was shuddering while exceeding 70 MPH. The vehicle was taken to the dealer, where it was diagnosed with an axle leak, and the contact was informed that there was no warning light illuminated for the failure due to the instrument panel failure. The axle leak was repaired; however, the failure persisted. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was notified of the failure, and a case was filed; however, no assistance was provided. The failure mileage was approximately 9,000.

I own a 2024 Toyota Grand Highlander Hybrid and am experiencing an intermittent knocking/clicking noise that appears to come from the drivetrain area. The noise occurs most often during low-speed driving and while turning left or right, particularly on the first drive of the day after the vehicle has been sitting overnight, but it has also occurred at other times while driving. The condition is intermittent and does not occur every trip, however it has been heard by multiple drivers. The noise is most noticeable during light acceleration combined with steering input at lower speeds. I have brought the vehicle to the dealership for inspection, but the condition has not yet been duplicated during testing. I am concerned this may indicate a developing drivetrain or axle-related issue that could affect vehicle safety if it worsens while the vehicle is in motion. I am submitting this report so the condition can be documented and evaluated for potential safety concerns affecting this vehicle model.

I had my front axle assemblies replace under T-SB-0082-24 around 20,000 to 25,000 due to rotational clicking noise per bulletin. The tsb uses the old part number which was the defective original part. The axles are failing agin at 50,000 and the dealer and toyota are refusing to fix it as they can’t replicate in shop. There is a new part number that was updated and supposedly fixed the issue but that is not the part that was installed in my car. They stopped the production line and updated the part at one point supposedly there was not enough grease in the cv joint boots causing premature wear. The old part number is still listed in the tsb even though it is superceded, tsb should be update or recall issued for all affected models to get the new updated part. Old part number 43420-0E340 new part 43420-0E341. Other side old part 43410-0E520 new part 43410-0E521. Toyota installed the old obsolete parts on my car in all paperwork for my work history and is refusing to install a working set of axles.