2024 Toyota Grand Highlander Engine Problems

The air conditioning system on my 2024 Grand Highlander failed due to a punctured AC condenser caused by road debris passing through the front grille during normal driving. The front fascia has large open apertures with no protective mesh or screening, leaving the condenser, radiator, and other heat exchangers directly exposed to rocks and debris. The condenser face shows multiple debris strikes, with one impact puncturing the core and causing complete refrigerant loss and AC failure at approximately 62,000 miles. The vehicle worked normally when parked and the AC was completely dead one week later due to the slow refrigerant leak from the puncture. Diagnosis was performed by [XXX] Toyota in [XXX], which confirmed the puncture was caused by road debris. The repair is not covered under warranty or my extended service contract because it is classified as outside damage, leaving owners to pay out of pocket for a design vulnerability. This is the same failure mode described in open ODI Defect Petition No. XXX covering 2024-2026 Grand Highlander vehicles. The same unprotected grille openings expose the engine radiator, meaning the identical debris path can puncture the radiator and cause coolant loss, engine overheating, and sudden loss of propulsion in traffic. The grille design leaves critical cooling components unreasonably vulnerable to everyday road debris. Photos of the punctured condenser and the dealer's written diagnosis are available. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11766783

Incident

Sep 15, 2026

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.

NHTSA ID

11761276

Incident

Aug 31, 2026

Horrible gas smell on the interior and exterier of vehicle after fueling up.

NHTSA ID

11760569

Incident

Aug 28, 2026

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.

NHTSA ID

11759560

Incident

Jul 15, 2026

The engine would not engage for 4-5 seconds when pulling out of my neighborhood. Gas pedal was all the way down and after a delay, the car rolled forward as if trying to start in 2nd/3rd gear. I am a cautious driver, but this is an unsafe scenario when pulling out into traffic.

NHTSA ID

11759500

Incident

Aug 25, 2026

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.

NHTSA ID

11758880

Incident

Mar 17, 2026

I had my car for service to be replace the wheel bearing on the right passenger side. Two weeks after my cooling engine light came out. Took to the dealership and they said there is a leakage in the radiator and needs replacing.

NHTSA ID

11758752

Incident

Aug 7, 2026

Vehicle intermittently fails to accelerate when accelerator pedal is depressed after stopping. Vehicle may move extremely slowly for several seconds and then suddenly regain power. This has occurred while entering/intersecting traffic and has resulted in near-collision situations. Dealer cannot duplicate the problem.

NHTSA ID

11756305

Incident

Aug 7, 2026

See attached Citizen's Petition Letter

NHTSA ID

11754975

Incident

Jul 20, 2026

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.

NHTSA ID

11750786

Incident

Jul 15, 2026

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

NHTSA ID

11746510

Incident

Jun 24, 2026

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.

NHTSA ID

11745922

Incident

Jun 18, 2026

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.

NHTSA ID

11734470

Incident

Apr 24, 2026

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.

NHTSA ID

11734376

Incident

Apr 14, 2026

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.

NHTSA ID

11725473

Incident

Mar 19, 2026

My car suddenly shook violently while at complete stop at a stop light. Also, the brake feels weird at times when slowing down.

NHTSA ID

11723452

Incident

Mar 6, 2026

All lights and warning system alerts suddenly came on. Hybrid System Malfunction. Once towed to dealership; stone came through large gap in front grill and put a hole in internal radiator. Not covered under warranty. Design flaw appears to be a problem in front grill.

NHTSA ID

11694480

Incident

Oct 12, 2025

My car accelerated very fast as I was attempting to pull into a parking spot. At first attempt brake did not work. Was able to avoid an accident. No sensors went off. Best described as an out of control amusement ride.

NHTSA ID

11690211

Incident

Sep 13, 2025

Toyota T-SB-0082-24 / Rotational Clicking Noise From Front Drive Shaft Assembly ( CV JOINT) CV joint defect poses an unreasonable risk to safety, especially if it fails while you are driving. An unreasonable risk is one where the potential for harm is much greater than the potential benefit of taking the risk. Driving with a compromised CV joint fits this definition because it can lead to a complete loss of vehicle control, which can result in a serious accident.

NHTSA ID

11685533

Incident

Sep 25, 2024

Description of Issue: I have experienced repeated incidents where the accelerator pedal becomes unresponsive (“dead pedal”) after coming to a stop. When pressing the pedal to accelerate, the vehicle does not respond at all for several seconds. Then, without warning, it suddenly surges forward with excessive acceleration once the power engages. This problem happens intermittently throughout a drive each day, often enough to be concerning. It occurs after being stopped at an intersection or in traffic. No warning lights or error messages appear before or during the issue. The delay followed by a sudden surge is dangerous, as I expect the car to move when I press the pedal, but it hesitates instead. When the vehicle finally responds, it accelerates quickly, which could cause me to lose control or collide with another vehicle. Safety Concern: This malfunction creates a significant safety risk. It puts myself, passengers, and other drivers in danger when the vehicle fails to accelerate as expected in high-risk scenarios such as crossing intersections, merging into traffic, or making left turns. The hesitation can leave the vehicle exposed in traffic, and the sudden lurch forward can cause unintended movement or rear-end collisions. Status: The problem has occurred multiple times under similar conditions and is ongoing. It has not yet been inspected or confirmed by a dealer or service center, but I have an apt Aug 24th. However, the malfunction is real, reproducible, and presents a serious hazard that could lead to an accident if not corrected. Many others with the same vehicle have expressed the same concern as well on forums and reported no fix after dealership appointments.

NHTSA ID

11684736

Incident

Aug 19, 2024

I've had consistent issues with the vehicle accelerating and shifting. These include sluggish acceleration, loss of power, sputtering, and limp mode. We've almost been hit by other vehicles almost 10 times because the vehicle has failed to accelerate when pulling into a roadway. The vehicle will start to accelerate slowly, then stop, then 5-10 seconds later will surge forward will the engine revs very high and is delayed shifting into 2nd gear. I've told my Toyota dealership about this numerous times but they keep telling me that there's no issue but there clearly is being that many others are experiencing the same exact problems. There's never been a warning lamp or message when this happens. This is a huge safety issue and my family is extremely lucky that we haven't been involved in a serious accident.

NHTSA ID

11681923

Incident

Apr 5, 2024

AC condenser has a leak and AC cooling not working-blowing hot air, making vehicle very hot inside. Toyota claiming from road debris damage, front grill not protecting condenser unit enough to allow this not to happen and will not cover under warranty. Seems like a manufacturer grill design problem not consumer. Toyota has no fix to the problem to protect condenser unit from this happening over and over again.

NHTSA ID

11680783

Incident

Aug 13, 2025

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.

NHTSA ID

11677818

Incident

Aug 1, 2025

It has a hard time shifting at times when the car has just been started

NHTSA ID

11674893

Incident

Jul 18, 2025

Over 1.5 years of owning my new 2024 grand Highlander platinum hybrid pro max I have had multiple incidents (6 documented now with toyota) where after coming to a complete stop I go to accelerate and the car shutters,sputters,lunges, and even looses power or goes into “limp mode”. I have been almost hit several times now by oncoming traffic because my grand Highlander completely loses power. It will not accelerate. After 5 seconds I typically hear loud groaning noises followed by two loud bangs and two violent lurches forward before my car finally regains power. No warning lights popped up on my dash any of the times my car has lost power. My dealership keeps telling me “no problem found” and that I am the only one with this issue. This is false. There are many complaints online and finally after I did not give up the dealership pulled a comprehensive RoB scan/report on my car and found multiple transmission failure codes on the transmission system/TCM. One “lack of acceleration code” was even dated two weeks before I bought my brand new grand Highlander with toyota. I received my grand Highlander with 6 miles on it. I was the first owner. My PDI “pre-delivery inspection date was one week after this transmission failure code”. When I presented this to toyota reps who finally met with me at the dealership they had nothing to say. Toyota knows about this problem and they do not know how to fix it. It is a serious safety issue and I refuse to allow someone to get hurt because Toyota will not be honest and relay this known issue. After the dealership and toyota reps told me I was the only one with this issue toyota officially released a service bulletin in March 2025 for a TCM flash reset/update to address sluggish acceleration, loss of power, and limp mode with the transmissions TCM when the hybrid systems battery is at 33% or less. My dealership installed the TCM update about 1.5 months ago and unfortunately my car has had two more instances since with loss of power.

NHTSA ID

11670662

Incident

Nov 15, 2024