2024 TOYOTA GRAND HIGHLANDER Complaints

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

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.

What component or system failed or malfunctioned, and is it available for inspection upon request? I was driving when I heard a loud boom, it almost sounded like a gunshot. Not noticing anything I continued driving. After a short distance I started hearing wind whistling. It was at this point I pulled over and saw my sunroof had shattered and there was a big hole. How was your safety or the safety of others put at risk? If I had not have the shade closed glass would have fallen into the car. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes, I brought the car to the Toyota dealership. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? I did call my insurance company but I am not sure if they actually inspected the damage. They have been dealing directly with the Toyota dealership service department. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No, that's why I continued to drive until I heard the wind whistling

My 2024 Used Toyota Grand Highlander Hybrid Platinum Max was at a slight decline stopped at a stop sign in Echo mode. The whole car began to violently shake and lurching forward. No one was in front of me and my foot was on the brake or I probably would have run into a car in front of me. The dashboard then flashed a warning about the hybrid system overheating. The only way to stop it was to turn off the engine, then turn it back on. The car then began driving normally. I have also had an issue with hesitation felt while accelerating 0-40 mph with study throttle. Upon researching both issues, they should be resolved with TSB calibrations to my car of T-SB-0028-25 and T-SB-0017-24. This is not an error that would come up when doing a diagnostic check on my car's computer per research I have done. I took my car to get the updates at Toyota of Redlands, CA, and they refused to do them unless they could recreate them themselves. I called Toyota to report this, and they said that each Toyota dealership/service is privately owned at their own discretion. I was basically told to return if I experience it again. I do not want to experience this again and they wouldn't take my word on it anyways. I feel like next time I could injure myself or someone else if this glitch happened again. I therefore would like to implore to make this a mandatory preventative TSB calibration for cars that have had this reported/models/year which mine has. This goes for any TSB calibrations should be done preventatively, but especially ones that can cause a potential accident like T-SB-0028-25 and T-SB-0017-24. Here is information on why this would not show up on a diagnostic test: Your Toyota didn't generate an error code because the shudder is a software calibration issue rather than a component failure. The onboard computer (ECU) only triggers a check engine light or throws a Diagnostic Trouble Code (DTC) when sensors detect a hard mechanical or electrical failure.

On [XXX], while driving my 2024 Toyota Grand Highlander at approximately 45-50 mph on a gusty, high-wind day, the rear panoramic moonroof/sunroof panel blew out and shattered completely without warning. The failure occurred as I rolled up the vehicle windows during the wind gust. Rapid window closure created a sudden spike in cabin air pressure — a documented pressure differential mechanism — that forced the moonroof glass outward until it shattered. There was no external impact of any kind. The glass, which is not laminated safety glass, scattered throughout the interior with occupants present. Component is available for inspection. This failure is consistent with NHTSA Investigation PE13-035 (Kia Sorento panoramic sunroof spontaneous breakage), in which ODI found glass shattering while in motion to be a safety hazard warranting engineering analysis. The same pressure-based failure mechanism applies here. This is a documented pattern on this specific model. Lemberg Law [XXX] ) analysis of NHTSA complaint data confirms spontaneous sunroof shattering among the top defects on both 2024 and 2025 Grand Highlanders, with Toyota denying warranty claims by alleging "outside influence" — disputed by owners and attorneys alike. No recall currently exists for this component. The rear seat directly below this glass is a primary location for child safety seats. Non-laminated glass shattering over rear occupants — including infants — represents an acute and unacceptable injury risk. I request NHTSA open a formal defect investigation into the panoramic moonroof/sunroof glass on 2024-2025 Toyota Grand Highlanders and evaluate whether a safety recall is warranted. I have photographs and have notified Toyota Motor North America in writing. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

3rd row seats do not want to lock into position, there is also broken plastic pieces from the locking mechanism area. Seats do not want to engage or disengage when trying to lay them flat. This had been a reported problem on other highlanders. This has been an issue since we purchased the vehicle in 2024. This is a safety issue because I fear they would fail in a crash.

It was noted that the drivers door weather strip deteriorated even though the car is less than 3 years old/ 47,000 miles. The dealer and the Toyota customer care said it is likely related to external factors and not covered under warranty. I keep the car in a garage. We have had other cars that are well over 10 years old but do/did not have this problem. This can potentially lead to damage of other components. I see on the internet that other owners of this car have encountered this same issue . There have been 3 safety recalls on this model, related to air bag, instrument panel and rear view camera. These have been fixed. There have been at least 5 Toyota technical service bulletins ( TSBs) published on this model. These were fixed after I brought it up with the dealer/ manufacturer. I was not contacted by the manufacturer proactively. TSB 0017-24 : hesitation felt while accelerating from stop. A software update was performed. TSB 0060-25 : Fuel level logic enhancement. A software update was made. TSB 0028-25 : Shudder sensation at stop. A software update was performed. ?T-SB-0082-24: CV axle issue: it was fixed T-SB-0111-24: vibrating hood.I notice the issue but did not fix it since the fix involves placing a foam under the hood, which may not fix the underlying issue and might cause other issues. I believe these issues are related to the manufacturing oversight and especially more frequent because it is a first year model .

While traveling at highway speed on I-75 northbound, the vehicle experienced a complete and total loss of electrical power. and propulsion. The following conditions were present simultaneously: - Complete loss of propulsion - Inability to shift transmission to neutral — vehicle could not be moved out of the active traffic lane - Complete loss of hazard lights — no ability to warn approaching traffic - Vehicle remained stranded in active highway traffic for approximately 15 minutes - Electrical power spontaneously restored after approximately 15 minutes - Vehicle was then driven off the interstate under its own power That was a life-threatening event. My wife and I could have been struck from behind by highway traffic with no warning lights, no ability to move the vehicle, and no way to signal distress. DEALER VISIT 1 — SATURDAY, APRIL 26, 2026 Dealer: Sarasota Toyota, Sarasota, Florida Complaint presented: Complete electrical shutdown on I-75 the previous day as described above Action taken by dealer: Performed recall repair for black screen issue Outcome: Vehicle returned to customer same day Post-repair symptom: Low voltage warning appeared on drive home from Sarasota Toyota Saturday afternoon Note: Dealer did not perform full electrical diagnostic. Dealer did not flag battery failure. Dealer did not retain vehicle for further investigation despite being informed of complete highway electrical shutdown the previous day. DEALER VISIT 2 — MONDAY, APRIL 28, 2026 Dealer: Germain Toyota of Naples, Naples, Florida Complaint presented: Complete electrical failure on I-75, low voltage warning after Sarasota repair, battery failure Findings: Battery confirmed dead. Alternator confirmed functioning normally. Dealer assessment: Condition described as unusual. Case escalated to Toyota Field Technical Specialist. Current status: Vehicle retained at Germain Toyota of Naples. Rental vehicle provided to customer.

There is an ongoing problem with Android connectivity. I have brought this to the dealer’s attention multiple times, but they continue to claim that my phone is not compatible. However, this same phone connects flawlessly and consistently in my other vehicles, so compatibility does not appear to be the issue.