2025 Toyota Grand Highlander Engine Problems

Rodent damage to plant based wiring to Engine Harness A and valve vacuum hose. Cost $1700 and 2 repairs.

NHTSA ID

11754788

Incident

Jul 30, 2026

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 ID

11750610

Incident

Jun 24, 2026

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 ID

11750573

Incident

Jun 17, 2026

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 ID

11750413

Incident

May 30, 2026

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 ID

11738734

Incident

May 19, 2026

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 ID

11735710

Incident

Apr 10, 2026

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 ID

11695992

Incident

Sep 15, 2025

The vehicle suddenly gave several warnings of “check engine visit your dealer”, “Hybrid system malfunction”, “AWD system malfunction 2WD activated” and “System malfunction visit your dealer.” The vehicle was bought new 4 weeks prior. Took it to the dealership and the technician said there was coolant all over the engine compartment and there was a leak somewhere. After inspection he told us that a small rock hit the radiator and caused damage. Told to replace the radiator and flush the system and it was not covered under warranty. After research was done, it was found there was a forum with hundreds of not thousands of people with the same issue. This has been an issue with the new OEM front grill not protecting the radiator and leaving it susceptible to be damaged easily. Toyota Corporate was called and said they were aware of the issue for some time. Even the Technician told us this is a common issue with this vehicle. Also if you place something inside the grill to protect the radiator, it will void the warranty.

NHTSA ID

11673489

Incident

Jul 14, 2025

The vehicle was in PARK and the IGN was in the ON/RUN position and the air conditioning was on. There was no one in the driver's seat but there was an occupant sitting buckled in the front passenger seat. The passenger heard a sound (possibly the ICE turning on) and he felt the vehicle move forward about five inches. He became worried about his safety and pressed the IGN button in order to turn the vehicle off. It could have pushed itself into other cars in the parking lot or pedestrians. A report was made to the local police department on the same day. This occurred in a retail parking lot. Video footage cannot be obtained as a police officer or insurance company must request it. I have not seen a check engine light nor any message prompts and it has not been inspected by a dealership.

NHTSA ID

11672869

Incident

Jul 1, 2025

I am submitting this complaint regarding a serious safety hazard and design flaw with the 2025 Toyota Grand Highlander Hybrid. While driving on a two-lane highway, our vehicle suddenly lost power and warning lights appeared on the dashboard. We were forced to exit the highway immediately (we were less than 0.5 miles to an exit). Shortly after pulling onto the off-ramp, the vehicle entered limp mode, significantly limiting its ability to function - all assist systems deactivated amd the car has a significant decrease in power. We were able to drive approximately half a mile to a nearby gas station, where we called for a tow. This situation left us vulnerable on a busy roadway, placing both us and other drivers at risk. The Toyota dealership diagnosed the issue as damage to the hybrid inverter radiator, allegedly caused by a rock or piece of debris entering through the front grille. We were told this was not covered under warranty, and to make matters worse, the necessary part is currently on backorder for three weeks to three months—leaving the vehicle undriveable. A significant concern is the design of the front grille, which has large, open gaps that allow ordinary road debris to enter the engine compartment. This leaves critical components like the hybrid inverter radiator exposed and vulnerable, even under standard driving conditions. After researching, I discovered numerous similar reports from other Toyota hybrid owners—including those with Grand Highlanders, Highlander Hybrids, RAV4 Hybrids, and Prius models—who have experienced the exact same issue. In nearly every case, drivers were told it was due to external damage and denied warranty coverage. This presents a clear and growing safety issue: 1. Sudden power loss on a highway or arterial road increases the risk of collision. 2. A critical hybrid system component is inadequately

NHTSA ID

11668786

Incident

Jun 22, 2025