2019 Toyota Sienna Transmission Problems

Your transmission has failed and needed to be replaced. You've experienced loud whining noises from the transmission, which is part of a broader problem affecting 2017-2020 models. This type of failure can be dangerous to vehicle occupants. The repair will likely involve transmission replacement or overhaul.

Your transmission unexpectedly lunches forward on its own, which nearly caused an accident. You're also hearing a whining noise coming from the transaxle. Toyota has a customer service program for 2017-2018 models with this same issue, but your 2019 van isn't covered. Fixing this will likely require transmission fluid service, internal transmission inspection, or possibly a transmission replacement or reprogramming.

Your vehicle suddenly lost all ability to move forward during rush-hour traffic on a highway, with no warning signs beforehand. After turning off and restarting the engine, the transmission would not respond to the Drive command, forcing you to use Reverse to reach the shoulder. A mechanic indicated the problem is likely either a faulty shift cable or complete transmission failure at only 71,000 miles. The transmission may need to be repaired or replaced, which could involve inspecting the shift cable connection or a full transmission overhaul.

Your transmission has developed a severe whining noise that started at 138,000 miles. Toyota has indicated your vehicle's VIN doesn't fall within the parameters of recall UA80 and won't repair the issue under that recall program. Addressing this will likely require transmission fluid analysis, filter replacement, or potentially transmission service or replacement depending on the underlying cause.

Your car hesitates and lurches between gears when you accelerate, making it feel sluggish—especially when the air conditioning is on. This problem started shortly after you bought the car, got worse after the fuel pump recall repair in 2020, and continues to happen more frequently now. The dealership and Toyota customer service haven't been able to resolve it, leaving you concerned about safety when merging in traffic. A fuel system and transmission inspection or repair may be needed to diagnose and fix the hesitation and gear-hunting issue.

While driving on the freeway during rush hour, your transmission suddenly lost power even though the engine was still running, forcing you to coast to the shoulder. Warning lights appeared for traction control and check engine. After restarting, the transmission would only shift into lower gears (1 or 2) and moved slowly, though it returned to normal operation by the next morning. The dealer diagnosed this as a coil issue and replaced it under warranty.