Skip to content
Transmission and drivetrainPart report

2020 Toyota Sienna Transmission and drivetrain Problems

Complaints
8about this part
Share
21%of 38 total for the year
Median mileage
30,723miles
Trend
Not enough dataFewer than 15 complaints, too few for a reliable trend.

NHTSA recorded 8 complaints about the transmission and drivetrain of the 2020 Toyota Sienna, 21% of the 38 complaints for this model year. Where a mileage was given, the median is 30,723 miles.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“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. …”

NHTSA complaint #11384761, filed 2020-12, 30,723 miles

“My Toyota sienna is a 2020, has 83,000 miles and has recently been squealing when I accelerate. I took the van to a local body shop and they said it seems to be my transmission. I called Toyota immediately and they knew that the transmissions were faulty and that they would try to work with Toyota to get it fixed. There is no way I can pay 9k for a new transmissions because they put in faulty ones.”

NHTSA complaint #11736554, filed 2026-05

“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.”

NHTSA complaint #11531570, filed 2023-07

“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.”

NHTSA complaint #11680231, filed 2025-08

“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.”

NHTSA complaint #11681131, filed 2025-08

Related service bulletins

Transmission and drivetrain: other model years

YearComplaintsShare of year
202222%
202185%
2020821%
2019715%
20182028%
20173824%
201634%
2015125%
201474%
2013148%
2012177%
2011305%
20101710%
200963%
2008389%
2007319%
2006404%
2005484%
2004894%
20031010%
2002137%
200163%
20006718%
1999115%
1998238%

Other parts of the 2020 Toyota Sienna

Fuel system
8 complaints
Electrical system
7 complaints
Engine
6 complaints
Other or unknown
6 complaints
Body and structure
4 complaints
Brakes
3 complaints
Steering
3 complaints
Air bags
1 complaints
Electronic stability control
1 complaints
Seats
1 complaints
Visibility (wipers, defrost, mirrors)
1 complaints
Wheels
1 complaints

← All problems reported for the 2020 Toyota Sienna

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 31, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology