general problems of the 2020 Toyota Sienna

Seven problems related to power train have been reported for the 2020 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2020 Toyota Sienna based on all problems reported for the 2020 Sienna.

1 Power Train problem

Failure Date: 05/07/2026

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.

2 Power Train problem

Failure Date: 04/01/2026

The vehicle is a 2020 Toyota Sienna. While driving, the engine suddenly shut off without warning, creating a dangerous situation and loss of power. This occurred while transporting children, increasing the safety risk. A mechanic inspected the vehicle and diagnosed a failure of the low-pressure fuel pump. The problem appears intermittently — sometimes the vehicle runs normally, and other times it stalls or loses power. The check engine light has turned on and off. This issue matches the known defect related to the denso fuel pump recall affecting many Toyota vehicles from similar model years. However, my VIN is not included in the recall. This is a serious safety concern because the engine can shut off unexpectedly while driving, which could lead to an accident. I believe this vehicle may have the same defective component as those included in the recall, even though it is not currently listed. The issue has been confirmed by an independent mechanic and the vehicle is available for inspection if needed.

3 Power Train problem

Failure Date: 08/02/2025

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.

4 Power Train problem

Failure Date: 05/12/2025

"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. ".

5 Power Train problem

Failure Date: 06/23/2023

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.

6 Power Train problem

Failure Date: 09/25/2022

For a month prior, there were intermittent incidents of the van shuddering and the rpm needle jumping upon ignition. Sometimes the van would have a hard time accelerating before jerking and driving normally. No issues before this started in late July and no indication when/where would occur. •September drove the van all day running errands. It drove normally. Filled up the gas tank (gulf gas station), then continued errands. About a half hour later, while at a stop sign, a notification appeared that the “traction control system has been turned off” and the check engine light came on. Tried to move through the stop sign, but the van would barely go. Applied the gas, but no results. Able to turn onto a side street and had to have it towed to Toyota of irving. The service advisor stated the issue was due due to bad gas and indicated the van needed to be flushed and the fuel injection system cleaned. Paid $725 for these repairs. •September started van in driveway. Shuddering and rpm needle jumping again. Drove normally. •September same as above. •September drove the van all day with no issues. Filled up with valero plus gas. As we pulled out of the gas station and sitting at the light, the traction control message and check engine light again appeared. The van would barely go to get us through the traffic light and into a nearby parking lot. Once we parked, the screen displayed the following message:"a malfunction in the electronic control of the engine, throttle, or automatic transmission has been detected. " had the vehicle towed to Toyota of irving. The service advisor called 2 days later to say they cannot detect any issues.

7 Power Train problem

Failure Date: 02/03/2021

Car has about 16,000 miles. When accelerating slowly from a stop, vehicle hesitates, shakes, and runs rough as it slowly progresses thru first, second, & third gears. After transmission gets in fourth gear, hesitation and roughness goes away. This issue is rapidly getting worse.


Other Power Train related problems of the 2020 Toyota Sienna

Power Train problems
7
Transmission Fluid Leaking problems
1


Sienna Service Bulletins
Sienna Safety Recalls
Sienna Defect Investigations