2019 Toyota Highlander

I am writing to formally document a series of unresolved mechanical issues with my vehicle, culminating in a complete transmission failure, and to request assistance in resolving this matter. The timeline of events is detailed below: *Winter 2024: I first noticed a persistent buzzing sound originating from the engine compartment. Because this symptom primarily occurred during low ambient temperatures, I initially attributed it to the cold weather. The mileage on this vehicle was around 50k miles. *Spring 2024: I contacted the dealership to report the noise. I was advised that the issue was likely related to a worn belt. Subsequent inspection, however, proved this diagnosis to be incorrect, and the root cause of the noise remained unresolved. *Fall 2024: The engine buzzing returned. Concurrently, a severe driveability issue emerged. On multiple occasions after shifting from Park to Drive, the vehicle failed to engage the gear properly, behaving as though it were in Neutral and preventing any acceleration. This would occur while driving and stopped at redlights, which posed a major safety concern as I was transporting my newborn and young child with me. * February 2025: The vehicle became entirely inoperable. Unfortunately, this failure occurred around 62k miles, AFTER my 60k mile warranty expired, (which i was unaware of). Given that these symptoms began during the winter of 2024 and were reported to the dealership early on, it is clear that the initial diagnostics failed to identify a developing and critical transmission defect. I conducted research and discovered this is a recurring issue with Toyota Highlanders, and other vehicles with the model UA80 transmission. Toyota posted a service bulletin, extending vehicles from 2017 & 2018 but have yet to address the 2019 through current models to date with reports of the same transmission issues.

The car is was a 2019 Toyota Highlander with approximately 125,000 miles. White Smoke started appearing in the exhaust. Quickly after that, the check engine light appeared and started blinking, meaning the engine was misfiring. We brought to the dealership, and they found that cylinder 4 of the engine was damaged (scoring on the inside of the cylinder wall). The engine was releasing metal particles in the oil. Further, the cylinder would not hold oil or coolant pressure, and was burning both oil and coolant. The only fix was to replace or rebuild the engine.

Our 2019 Toyota Highlander currently has 54,605 miles. In August 2025, when the vehicle had 50,236 miles, we brought it to the Toyota dealership to address a whining noise coming from the transmission. At that time, the vehicle was still under the manufacturer’s warranty. The dealership performed a transmission service during that visit. Within the following weeks, however, the whining noise returned, and the vehicle began experiencing hard and delayed shifting. Our children and grandchildren have recently moved to Washington, and we had planned to drive there to visit them. Unfortunately, we are now reluctant to drive the vehicle due to safety concerns, as we have been advised that the transmission may be failing. The dealership has now recommended a full transmission replacement. Because the original concern was reported while the vehicle was still under warranty, we believe the issue should have been properly diagnosed and resolved at that time. However, the problem was not addressed, and the vehicle is now outside the warranty period, with Toyota declining to cover the cost of the replacement transmission. Given that the problem was first reported while the vehicle was under warranty, we are requesting that Toyota reconsider covering the transmission repair or replacement.

1. What component or system failed or malfunctioned? System: Power Train: Automatic Transmission Specific Component: UA80 8-Speed Automatic Transmission (Internal Failure) Available for Inspection: Yes, the vehicle is currently available. 2. How was your safety or the safety of others put at risk? While merging onto the highway, the transmission failed to upshift, resulting in a sudden and unexpected loss of acceleration. The vehicle could not reach or maintain highway speeds (speed limit). This created an immediate hazard as I was unable to keep up with the flow of traffic, forcing me to make an emergency exit across multiple lanes while moving significantly slower than other vehicles. The loss of motive power increased the risk of a high-speed rear-end collision. 3. Has the problem been reproduced or confirmed by a dealer? Yes. The problem was confirmed by Heritage Toyota Service. The technicians confirmed an internal transmission failure. A secondary consultation with a transmission specialist (AAMCO) also identified the failure as a known mechanical defect common to this transmission model. 4. Has the vehicle been inspected by the manufacturer... or others? Yes, it has been inspected by the authorized Toyota Dealership listed above. I have also reported the issue to Toyota Brand Engagement (National), but a corporate field inspection (DSPM) has not yet been performed. 5. Were there any warning lamps... or other symptoms? Symptoms: A distinct whining noise from the engine/transmission area that increased with vehicle speed. Prior Events: The vehicle was taken to the dealer specifically for this noise. The dealer performed a fluid change and released the vehicle. The catastrophic failure (loss of power) occurred less than 24 hours after leaving the dealership. No dashboard warning lights illuminated prior to the loss of power.

In early January 2026 there was rough/delayed shifting, whining noises, and fluid leaks. Probably linked to the faulty UA80E/F transmission type. The check engine light came on 1/15/26, I took it into a local repair shop. The mechanic flushed and changed the transmission fluid, replaced all of the spark plugs and the serpentine belt. I picked it up on 1/16/26. There was still shuddering, strange sounds (whining/grinding), and hesitation. On 1/20/26 I drove it and the rough/delayed shifting, whining noises, hesitation and burning smell started happening. The car completely broke down on the freeway and wouldn't drive at all. I had to slowly pull over to the shoulder of the freeway and have the car towed to the repair shop. They inspected it and said I need a new transmission, and it cannot be fixed. I believe the next steps are to have it towed to the toyota dealership to have it looked at.

Transmission failure resulted in sudden loss of power while driving, creating a safety risk in traffic. Vehicle was unable to accelerate and required immediate repair. Put myself and my children at risk, as the car suddenly died while I was driving it. Prior to this, there were not issues. Has been routinely maintained and only has approx 83k miles. Toyota agreed that the transmission is the only issue with my car but won't cover the cost to replace it (10k) or the cost of a loaner vehicle. I have been without a car for almost a month while the (refurbished) transmission is on backorder.