2024 Toyota Grand Highlander

At 5:16 pm, CST. I was stopped at a stop sign headed west on a 25 mph road crossing a 30 mph road (that does not have a stop sign) in Illinois. After waiting for a an appropriate gap in traffic, I attempted to accelerate though the interesting. I released the brake pedal and attempted to accelerate. The vehicle barely accelerated. The engine seemed to minimally climb in RPM and only accelerated minimally out into the cross road. This lasted approximately 1-2 seconds. AT this point I was fully into the first lane of traffic. I then fully depressed the accelerator to try to get the vehicle to respond and after approximately a 0.5 to 1.0 second delay the engine fully responded and I was able to accelerate out of the oncoming cross traffic. This is by no-means the first time this behavior has happened with this vehicle but it is the first time I'm reporting it to the NHTSA.

Sometimes, when trying to accelerate in certain situations, the vehicle accelerator pedal will not respond or the engine stutters and won't immediately respond to input and the vehicle seems to stall. This has been scary several times in traffic. The vehicle originally would throw an engine code on the dash about system failure and was taken into the dealer after several of these incidents and a software updates was performed, but it still happens randomly although now with no code.

While driving on a highway at highway speed of approximately 62 miles per hour, a rock from the highway went through the front grille's hole, and punctured the area of the radiator, resulted in a large loss of coolant, and the vehicle's speed suddenly lost highway speed and lost propulsion on the highway, while driving at a highway speed. Thankfully noone was driving behind me. However, If someone was behind me, they would have hit me from the rear due to my loss of propulsion.

I've had consistent issues with the vehicle accelerating and shifting. These include sluggish acceleration, loss of power and sputtering when we've come to a complete stop and starting to move again. We've almost been hit by other vehicles at least over 20 times because the vehicle has failed to accelerate when pulling into a roadway. 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 extremely high 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 had patience and avoided us. I've also found that this issue always happens when the hybrid battery shows that it only has a charge of 3 bars. It seems that the engine, transmission and hybrid battery don't know how to communicate when the battery charge gets that low. This has been happening since Dec 2023 when I bought the vehicle and the dealer has never been able to duplicate or find any error code, they are refusing to fix a known issue when many others are experiencing the same issue. There are Toyota Technical Service Bulletins (TSBs) out there regarding this problem but my dealer told me they won't do anything as it could label my vehicle a lemon. This is creating an unnecessary safety risk for me and my family.

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.

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.