2019 Toyota Highlander

My 2019 Highlander was driving totally normal, when all of a sudden the transmission started slipping and then would no longer accelerate. I was on a windy back road in Alaska with no service, so after letting it sit for a bit I tried to drive it again. It then drove maybe 1/2 more miles before slipping completely and no longer accelerating. No check engine lights came up. I got it towed to my house where a mechanic took a quick scan and said there was a number of transmission codes popping up.

Sporadically, when starting up the vehicle, from the overhead console, it emanate a loud, ear piercing sound that is painful to one's ears. Apparently, this is a KNOWN issue with 2019 Toyota Highlanders in the Limited Platinum trim level. This issue has been presented to the dealership numerous times (DARCARS Toyota Frederick) with their claim they could not recreate the issue. I have provided video evidence but still no action was taken. Now out of warranty, it occurs more frequently now with this piercing noise.

The contact owns a 2019 Toyota Highlander. The contact stated that while driving approximately 30 MPH, the vehicle stalled; the contact shifted the vehicle into park(P) and restarted the vehicle for the vehicle to return to normal operation. No warning lights were illuminated; however, the “Auto START/STOP Failure” and “See Dealer" messages were displayed on the instrument panel. The failure reoccurred on several occasions. The vehicle was taken to a dealer, where it was diagnosed, and determined that the wiring harness needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 86,530.

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.

What component or system failed or malfunctioned, and is it available for inspection upon request? 12V battery How was your safety or the safety of others put at risk? Vehicle unable to start. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Inspected by independent service center. Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No warning of impending failures. 2/17/2020, vehicle purchased new from Toyota of Morristown (NJ). 2/23/2023, vehicle's (3 year old; 1 week outside of warranty) original OEM 12V battery failed and was replaced with Toyota OEM 12V battery (Part #2880031291) by independent service center ($376.61). 12/18/2025, vehicle's (less than 2 year old) replacement Toyota OEM 12V battery failed and was replaced with Toyota OEM 12V battery by independent service center ($407.88).