4 complaints reported

2020 Toyota Sienna Power Train

Owner-reported problems and safety issues filed with NHTSA. Review common failures, severity levels, and complaint trends over time.

Reports
4
Crashes
0
Fires
0
Injuries
0

Complaint Timeline

Chronological view of owner reports

Dec 2025

A catastrophic failed automatic transmission; UA80E of Toyota Sienna 2020 at 85,000 miles. It occurred while I've been driving downhill. No warning lights, not overheating, no diagnostic ODB code, no other indications prior to the failure. Failure created a substantial safety risk for myself, my four passengers and other road users. Sudden loss of transmission function could lead to potential dangerous situation. Minivan was towed to the nearest Toyota dealer where transmission assembly was confirmed for replacement.

Type: Vehicle, Vehicle: 2020 TOYOTA SIENNA, Manufacturer: Toyota Motor Corporation
Incident: Feb 2025
Aug 2025

"I've owned the vehicle for five years, and recently I started hearing a whining noise coming from the transmission. After doing some research, I discovered that I'm not alone in experiencing this issue. The dealer told me that the transmission itself is the problem and recommended replacing the entire transmission. However, a second opinion suggested that this kind of noise isn't normal. I'm worried about safety because, although it's just a whine right now, I fear it could fail unexpectedly. I have a child in a wheelchair, and ensuring my vehicle's safety is very important to me."

Type: Vehicle, Vehicle: 2020 TOYOTA SIENNA, Manufacturer: Toyota Motor Corporation
Incident: Dec 2025
Nov 2023

My car was not shifting gears, and it would go into brief periods of erratic acceleration. I took it to the dealer service dept. The transmission went bad. It had metal pieces broken off inside it. The car is 3 years old and only has approximately 70,900 miles on it. It was dangerous to drive. It put me, my kids, and other drivers at risk due to the erratic shifting it would do while driving. The issues started slowly on 6/23/23. The check engine light was on by 6/24/23.

Type: Vehicle, Vehicle: 2020 TOYOTA SIENNA, Manufacturer: Toyota Motor Corporation
Incident: Jun 2023
Dec 2020

PURCHASED RENTAL PROGRAM VEHICLE AND IMMEDIATELY HAD VEHICLE SERVICED AT THE DEALERSHIP. RECEIVED A PHONE CALL FROM SERVICE ADVISOR THAT AUTOMOTIVE TECHNICIAN HAD FOUND A MECHANICAL PROBLEM. IT WAS STATED THAT A HOSE HAD COME LOOSE/APART IN THE AXLE AND FLUID WAS LEAKING. NOW, WE HAD PURCHASED VEHICLE DAY BEFORE AND THE FOLLOWING DAY DROPPED VEHICLE FOR SERVICE AT DEALERSHIP. AS A CONSUMER, I NEED A MAINTENANCE BASELINE. THE BRIEF TIME DRIVING THE VEHICLE, THERE WAS NO VISIBLE/AUDIBLE CLUE THAT MECHANICAL ISSUE WAS PRESENT. EXACT DESCRIPTION OF WARRANTY WORK PERFORMED [DRIVER SIDE FRONT AXLE ASSEMBLY, AXLE COMING APART INTERNALLY] REPLACED DRIVER SIDE FRONT AXLE ASSEMBLY. FORTUNATELY, VEHICLE WAS BEING SERVICED AND THIS COMPONENT DID NOT FAIL WHILE IN MOTION.

Type: Vehicle, Vehicle: 2020 TOYOTA SIENNA, Manufacturer: Toyota Motor Corporation
Incident: Dec 2020

Trend Over Time

Complaints by year

Quick Summary

The 2020 Toyota Sienna has 4 Power Train complaints on file. Review the timeline above for detailed owner experiences.