46 of the
433 complaints filed about the Toyota Grand Highlander
are about the engine —
11% of everything owners reported.
The worst model year for it is 2024.
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 complaint #11758880 — an unverified report by a vehicle owner.
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 complaint #11756305 — an unverified report by a vehicle owner.
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 complaint #11750786 — an unverified report by a vehicle owner.
After coming to a complete stop at a stop sign or stop light, then trying to go, the vehicle will stall. It will not go when given gas. The first time it happened, I was at a busy intersection with oncoming traffic coming towards me with the pedal to the floor, nothing would happen for 5-10 seconds. It was terrifying. Thank god the car coming towards us went around in time. It then happened again in my neighborhood a week later. Thankfully that time I wasn’t in traffic. I have noted that it seems to happen when very hot outside (Florida July summer) and air is on full blast. Also seems to be happening only during the first trip of the day, within the first 5-10 minutes of said trip. The dealership has not been able to recreate this to see for themselves. I think it would have to be with them overnight and they start it/drive it for the first time that day. It has now happened a total of 3 times since I’ve been driving it (2.5 months). I have 3 children and very worried I will get t-boned one day when it stalls next. I love my car so much so it’s heartbreaking that I have to drive it in fear. No lights/warnings/messages when this happens.
NHTSA complaint #11750573 — an unverified report by a vehicle owner.
This vehicle has just over 18,000 miles on it and is 14 months old. It has a manufacturer design defect that allows small stones or birds to hit and puncture the air conditioning condenser. It is a known defect and Toyota refuses to warranty their product, forcing the consumer to pay out of pocket $1,500-$1,700 for repairs. Oddly, the sister Lexus vehicle has a screen over the condenser to prevent this.
NHTSA complaint #11750610 — an unverified report by a vehicle owner.
Radiator issue summer of 2025, when in back to back traffic at low speeds my vehicle overheated at a stand still took vehicle in to dealership with no real answers. The following summer 2026 same scenario but the engine was smoking. Took into dealership and they stated the connection for the radiator fan was disconnected which meant it was not colling the engine. A month later the AC is blowing hot air when AC is set to the coolest setting, scheduled another appt with dealership likely another radiator issue. Fuel gauge inaccuracy. Manual states 17 gallon tank capacity but my car states empty and can only fill the tank with 14 to 15 gallons. Dealership had no help and stated it does that to protect the hybrid engine. Transmission shifting issues, in the summer hotter temperatures I notice at times the transmission has difficulty shifting in lower gears and really revs up the RPMs to shift sometimes. At times the the transmission shift is jerky or harsh when going speeds form 20- 40 mph.
NHTSA complaint #11750413 — an unverified report by a vehicle owner.
Component: Automatic transmission, 2026 Toyota Grand Highlander Hybrid MAX Platinum AWD. Available for inspection. Purchased new 11/21/2025 at zero miles. Beginning ~2000 miles (est Feb 2026), intermittent transmission malfunction during acceleration: transmission holds gears at elevated RPMs beyond expected shift point, then shifts harshly or shudders violently. Documentation began 6/1/2026; current odometer 8936 miles. Occurs from 22–64 mph, most commonly 30–44 mph, in Normal and Sport modes, after cold starts, extended driving, and brief stops. RPMs typically hang at 3500–4000 before shifting. Documented incidents over the last month: June 1, 2026, 3:20 PM: Approximately 1 min after cold start, turned right at a light to 33 mph. Violent shake and abnormally loud acceleration during gear change. June 2, 2026, 3:00 PM: Turning right and accelerating after driving approximately 1 min, transmission revved high; had to release throttle to force the shift. June 11, 2026, 4:40 PM: After cold start, driving up a small incline about .4 miles away, transmission revved high and delayed shift at 35–45 mph. June 12, 2026, 3:17 PM: After 17 minutes of driving, accelerating from a cloverleaf around 25 mph to 64 mph, revved at 4000 June 19, 2026, 3:00 PM: After 2 hours of driving and a 5 min stop, turning right out of a shopping center, transmission hung up three consecutive times at 35–40 mph, RPMs at 3500–4000. June 20, 2026, 11:17 AM: Accelerating off a cloverleaf at 57 mph. RPMs hung at 4000 before shifting. June 30, 2026, 10:23 AM: Pulling out of neighborhood after backing out of driveway. RPM hang at approximately 22 mph, then again at 43 mph Safety risk: Unexpected RPM surge and violent gear change during acceleration on highway on-ramps, cloverleaf merges, and intersections creates unpredictable vehicle response at speed, presenting collision risk to driver and surrounding vehicles Dealer/service: Not confirmed by dealer. Assessed at ~6000 miles with no issues found
NHTSA complaint #11747505 — an unverified report by a vehicle owner.
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 complaint #11746510 — an unverified report by a vehicle owner.
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 complaint #11745922 — an unverified report by a vehicle owner.
Failed System: Fuel Injector Failure (?) at high speeds, under load (uphill), causing an immediate and life threatening loss of power. While traveling on the highway, going up mountainous areas, the vehicle loses power and shakes violently. During multiple repairs/visits, the dealerships state that it is the failure of fuel injectors. They are replaced, and it happens again with the same explanation. Safety: Three times my family has lost power at 70mph while traveling uphill surrounded by many cars. The last event ended in a a scary and close interaction with an 18 wheel truck that was unable to stop as we lost power. Dealer Confirmation: The dealer has confirmed, on two separate occasions, that the fuel injectors needed replaced. The vehicle has 3,000 miles on it. At 2,000 miles, damage was found to the fuel injectors. They were replaced and the car was placed back in my possession. At 3,000 miles, the incident occurred for the 3rd time and damage was again found with the fuel injectors. Inspection: Dealerships as well as Toyota's field technician have inspected/repaired the vehicle 2 times and is currently at a dealership for the 3rd time. Warning messages: After the incident occurs, multiple warning lights appear (check engine and hybrid system malfunction).
NHTSA complaint #11740216 — an unverified report by a vehicle owner.
On multiple occasions (four) my 2025 Toyota Grand Highlander Hybrid Max has failed to accelerate when I push the gas pedal. Once in traffic, which was extremely scary and a huge hazard. I have contacted the dealership about this issue and have not heard back from them. It has been almost 2 weeks. No warming lamps turned on and this issue lasted about 15 seconds each time. I press the gas, the car does not respond other than an audible RPM raising sound.
NHTSA complaint #11738734 — an unverified report by a vehicle owner.
I was driving on in the left most lane on a highway at 70 miles speed with multiple trucks speeding from behind. My car suddenly lost acceleration and saw multiple warning messages on my car display. I barely managed to save my car from being hit by the trucks speeding from behind, applying emergency lights and steering my vehicle from the left lane to the right side of the highway. After towing the car to nearest dealer I understood that a stone went through the front grill of the car and it got the radiator converter leaking all the coolant and that created the loss of acceleration. This is a safety issue in the design of the car grill as it has unusually large holes leaving a critical part vulnerable and failure leads to loss of acceleration and a safety hazard. For similar other hybrid models in Lexus or Toyota Sienna the same grill is protected with smaller vents in the grill.
NHTSA complaint #11735710 — an unverified report by a vehicle owner.
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 complaint #11734470 — an unverified report by a vehicle owner.
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 complaint #11734376 — an unverified report by a vehicle owner.
I purchased this vehicle new from Toyota of madison in Indiana on 3/26/2026. It had 300+ miles on it. Had it for just a week before this warning light came on while idling or driving very slowly..… High Coolant Temp. Pull over in a safe area immediately. My temperature gauge was in the red. I pulled over. Called closest dealership who stated closed for Easter. After several hours of personal researching on the internet of a potential cause , I examined the engine only to find that my Radiator Fan had been UNPLUGGED!! No wonder the engine was overheating. I currently own 4 corollas, one 2025 tundra, and one sienna. I have never had this issue with Toyota. Why was the radiator fan unplugging and Who unplugged this radiator fan and forgot to plug it back?????
NHTSA complaint #11729249 — an unverified report by a vehicle owner.
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 complaint #11725473 — an unverified report by a vehicle owner.
Poor acceleration from 0 to 40. Vehicle will start shuttering at a dead stop. The engine has shut off once with this issue. It happened around 4800 miles.
NHTSA complaint #11695992 — an unverified report by a vehicle owner.
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 complaint #11694480 — an unverified report by a vehicle owner.