Power Train Problems of Toyota Sienna - part 1

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.

See all problems of the 2020 Toyota Sienna 🔎.

On April 15, 2026 report filed with NHTSA from an accident-causing property damage due to a failure in the shifter mechanism while the vehicle was parked, ignition off, no keys in the vehicle and the brake pedal was not pressed. Manufacture initiated an investigation after we contacted their customer care line. Our vehicle was taken to a Toyota dealership on March 11, 2026. We received an email on April 13, 2026 stating Toyota's inspection did not identify any evidence that this incident was a result of a concern with the operation of our vehicles gear shift lever. We retrieved our vehicle from the dealership on April 20, 2026. On April 21, 2026 from our driveway the shift lever fell out of park into drive with the ignition off, no keys, and the brake pedal not pressed. Toyota claims no responsibility! how is this possible when they know there are active recalls for the same issue on earlier models? this is a massive public safety risk considering the vehicle can rollaway without the ignition even being on! I will continue to report this issue every time the shift lever falls out of park until resolved.

See all problems of the 2015 Toyota Sienna 🔎.

On April 15, 2026 report filed with NHTSA from an accident-causing property damage due to a failure in the shifter mechanism while the vehicle was parked, ignition off, no keys in the vehicle and the brake pedal was not pressed. Manufacture initiated an investigation after we contacted their customer care line. Our vehicle was taken to a Toyota dealership on March 11, 2026. We received an email on April 13, 2026 stating Toyota's inspection did not identify any evidence that this incident was a result of a concern with the operation of our vehicles gear shift lever. We retrieved our vehicle from the dealership on April 20, 2026. On April 21, 2026 from our driveway the shift lever fell out of park into drive with the ignition off, no keys, and the brake pedal not pressed. Toyota claims no responsibility! how is this possible when they know there are active recalls for the same issue on earlier models? this is a massive public safety risk considering the vehicle can rollaway without the ignition even being on! I will continue to report this issue every time the shift lever falls out of park until resolved.

On April 15, 2026 report filed with NHTSA from an accident-causing property damage due to a failure in the shifter mechanism while the vehicle was parked, ignition off, no keys in the vehicle and the brake pedal was not pressed. Manufacture initiated an investigation after we contacted their customer care line. Our vehicle was taken to a Toyota dealership on March 11, 2026. We received an email on April 13, 2026 stating Toyota's inspection did not identify any evidence that this incident was a result of a concern with the operation of our vehicles gear shift lever. We retrieved our vehicle from the dealership on April 20, 2026. On April 21, 2026 from our driveway the shift lever fell out of park into drive with the ignition off, no keys, and the brake pedal not pressed. Toyota claims no responsibility! how is this possible when they know there are active recalls for the same issue on earlier models? this is a massive public safety risk considering the vehicle can rollaway without the ignition even being on! I will continue to report this issue every time the shift lever falls out of park until resolved.

2019 Sienna xle with 77,000 miles has a ua80 transmission is whining at the final gear per imperial Toyota milford MA service center. They want to replace the transmission for 9,000 usd and Toyota corporate refuses assistance. It appear to be a common defect which could lead to transmission lockup if the gear fails.

See all problems of the 2019 Toyota Sienna 🔎.

Loss of power highway speeds, jerky shifting, “sealed” transmission leaking fluid. Check engine light and service required light. I have noticed poor performance with this vehicle before and reported it to the dealer to no avail. Toyota has enacted “customer support program zjc” but the dealership will not honor.

See all problems of the 2017 Toyota Sienna 🔎.

My transmission has started with a whining noise, Toyota knows about this issue with thousands of cases regarding the faulty transmission, yet only a few are being covered under a customer support bulletin zjc. We need to hold Toyota responsible for this issue. We were just told today they won't help us at all. Yet now we are left with a van that we can't use and if we decide to fix it for 10k they are saying the transmission is backordered for months we had to pay Toyota $180 to diagnosis what we already knew was wrong with the vehicle so they would even consider if they would cover it.

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.

The contact owns a 2015 Toyota Sienna. The contact stated that while the vehicle was parked, and the shifter lever was turned off, it unexpectedly fell down, causing the vehicle to shift into drive and roll down the street, where it crashed into a house. At the time of the incident, the vehicle was occupied by one three-year-old and two six-year-old children. One of the six-year-old occupants attempted to move the shifter into park while another attempted to steer the vehicle. The passenger-side sliding door was ajar. There were no warning lights illuminated. There were no reported injuries, fire, or airbag deployment. A police report was filed. The vehicle was taken to a local dealer; however, the failure was not diagnosed or repaired. The manufacturer was contacted, but declined the claim. The failure mileage was approximately 119,274.

I am writing to report a safety defect regarding the 8-speed automatic transmission in my 2017 Toyota Sienna. The vehicle exhibits severe hesitation during acceleration, harsh shifting, and a high-pitched whining noise, specifically consistent with the 'whine of death' described in Toyota's customer support program zjc and related technical service bulletin t-sb-0160-18. Despite these identical symptoms, my vehicle’s VIN is not included in the coverage list. This hesitation during acceleration creates a serious safety issue, as the car fails to accelerate unexpectedly when attempting to merge or cross traffic. My vehicle is equipped with the ua80f/e transmission, which is documented to have a faulty assembly (improperly bent washer tab). I request that NHTSA investigate the exclusion of my VIN from this program, as the defect poses a significant risk to passenger safety and the safety of others on the road.

The transmission started making a whining sound. There is a Toyota customer support bulletin pol19-04 that mentions this issue however the dealer says this car is not covered.

My 2018 Sienna had developed a whining noise when accelerating. After taking it in to the mechanic, they advised the transmission was failing. Estimated price tag of $6500-7000 to repair. The vehicle has less than 140k miles. Looking at different issues with this make/model and year, it seems like its rather common. I bought a Toyota for its reputation of getting at least 200k if not more miles. I called both the dealer and Toyota themselves. Both said too bad, so sad - nothing they could do for me.

See all problems of the 2018 Toyota Sienna 🔎.

The contact owns a 2017 Toyota Sienna. The contact stated that while starting the vehicle, reversing, and then while driving 20 mph, there was an abnormal whining sound coming from the front of the vehicle. A dealer was contacted. The vehicle was taken to the dealer and was currently being diagnosed. The vehicle was not repaired. The contact related the failure to technical service bulletin: TSB-0160-18 (transaxle whine noise, harsh shift, mil on, or reduced power); however, the VIN was not included in the bulletin. The manufacturer was notified of the failure and referred the contact to the NHTSA hotline to report the failure. The failure mileage was 120,000.

Transmission has been whining. A p27137f code appeared and the vehicle is only in 2wd mode currently. Concerned to drive vehicle due to further damaging transmission or getting stuck while on the road.

The contact owns a 2018 Toyota Sienna. The contact stated that while driving 30 mph and ascending a hill, the vehicle started making an abnormal whining sound and hesitated while accelerating. The vehicle was driven to the dealer to be diagnosed. The vehicle was diagnosed with transmission failure. The manufacturer was notified of the failure. The failure mileage was approximately 126,000.

My husband and I bought this van brand new 6 years ago. We have taken very good care of it and have had it serviced only at the dealership. We haven’t had any problem with the van outside of regular maintenance. On 10/29/25, I had a van full of children when I felt a slip in my acceleration and a warning light came on that read, “ a malfunction in the electronic control of the engine, throttle, or automatic transmission has been detected. Contact your dealer in order to have your vehicle inspected immediately. ” thankfully, I was able to get it to the parking lot. The van didn’t leave that parking lot until the next morning when we took it directly to the dealership. That is when we were told the solenoid and the transmission had gone out. We had to have the whole thing replaced. The van only had 89,388 miles on it.

Shifter not shifting into park even when in park causing it to roll even when you think it’s in park.

See all problems of the 2004 Toyota Sienna 🔎.

The contact owns a 2017 Toyota Sienna. The contact stated that while driving at an undisclosed speed and attempting to accelerate, the vehicle briefly hesitated before shifting hard into gear. The contact stated that after the failure, there was an abnormal whining sound coming from underneath the vehicle. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who was unable to provide a specific diagnosis for the cause of the failure; however, the contact was informed that there were known issues with the transmission of similar vehicles. The vehicle was not repaired. After investigating the failure, the contact related the failure to the customer support program bulletin: zjc. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA hotline for assistance. The failure mileage was 40,000.

My 2017 Toyota Sienna has a whine noise coming from the transmission. Brought it to the dealer I have done everything at for this van and they say it’s the transmission and it will cost more than it’s worth. There’s a csp-zjc but my VIN isn’t on there. It’s presenting the same exact problem as the csp. Unbelievably, Toyota cares isn’t doing a “good will” service fix. Very disappointed in their customer service.

My 2017 Sienna has whine noise coming from transmission, the vehicle was inspected by Toyota dealership and confirmed that the noise is coming from transmission. Toyota has already issued a recall for the 2017 Sienna with transmission ua80 under program zjc. My vehicle has the same issue, however, it is not being covered as it is ua80e. This issue seems common among all the 2017 model irrespective of transmission number. However, Toyota is not providing support to all customer and have limited to a only one transmission number.

While driving my 2021 Toyota Sienna hybrid, the vehicle suddenly displayed a low oil pressure warning, immediately lost power, and entered limp mode. I was able to pull over safely, but the engine then suffered a catastrophic failure — a connecting rod blew through the engine block, leaving large metal fragments inside the engine compartment. The vehicle is completely inoperable. Prior to this event the van sometimes idled rough and shook slightly on startup when transitioning from battery to gasoline engine after sitting, but it drove normally otherwise. I have performed regular oil changes and routine maintenance according to Toyota’s schedule. Safety concern: this failure happened suddenly and without warning. If it had occurred at highway speeds, it could have caused a serious crash due to loss of power or debris from the engine. This presents a significant safety hazard for drivers and passengers. Toyota has issued TSB t-sb-0104-21 for the 2021 Sienna hybrid’s a25a-fxs engine addressing “mil on with low oil pressure” conditions and dtcs p05202a/p052477 with milky or discolored oil. This suggests Toyota is aware of oil pressure and lubrication issues on this engine family. My catastrophic failure appears consistent with a loss of oil pressure or lubrication. I am filing this complaint to alert NHTSA of a possible defect or safety issue affecting 2021 Toyota Sienna hybrid engines that can result in sudden catastrophic engine failure.

See all problems of the 2021 Toyota Sienna 🔎.

Transmission whine and hesitation. Low gear it will hesitate from stop. Know issue with this transmission. There should be a recall on all ua80 transmissions.

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.

In July of 2025 my 2017 Sienna started making a whine noise. Took it to mechanic and he stated it was likely coming from transmission but recommended we take it to Toyota dealership to confirm. So we took it to Toyota and sure enough they said the transmission was failing. They said it was due to high mileage but it only had just over 150,000 at time of incident. After doing some research on line and talking with other Sienna owners I believe our Sienna should fall under the ua-80 recall.

Sound coming from engine / transmission other issues with the 2 ruber seals on the minivan keep worping out I looked on all the forms everyone is making the same complaint I toook it to Toyota they just put tape and its off again they didnt help for a perminent fix back door is miss alined pasanger side sliding door sometimes does not close takes 3-4 atempts pressing the button.

My husband parked our minivan and came in to pick up the kids. While he was inside the library, the van went out of park and hit a fire truck in the parking lot. It seems this has been an issue with Toyota Siennas in the past but I do not see it reported yet for its year 2015. Our van had damage to the front fender, hood, and surrounding area and needed repair. We obviously didn’t have any idea this was possible nor noticed anything since purchasing this van recently. I have read online that a Toyota Sienna cannot be turned off without being in park. Since my husband was not in the vehicle when it crashed in the parking lot, it is clearly a defect of the vehicle.

My transmission (ua80e) has started to steady whining noise when driving and has some choppiness when changing gears. The local Toyota dealership is recommending full replacement, the dealership said it is out of warranty. Toyota headquarters released a customer support bulletin zjc in 2019 covering this issue for the next 10 years, but they are saying they will not cover it under this bulletin even though my model year, transmission and symptoms all match the described issue.

Sever transmission whine started at 138k miles over a year ago. Toyota will not fix issues under recalled ua80 transmission. Said my VIN doesn’t fall within recall.

Transmission has failed and been replaced. This is part of issues from 2017 to 2020 tranny failures, loud whining and needing to be replaced. Tranny failure is very dangerous to the occupants. Toyota has failed to warranty these.

The contact owns a 2017 Toyota Sienna. The contact stated that while driving approximately 30-40 mph and releasing the accelerator pedal, the vehicle made an abnormal whining sound that progressively became louder. The vehicle was taken to the dealer, where it was diagnosed, and it was determined that the transmission needed to be replaced. The vehicle was not repaired due to the cost. The manufacturer was notified of the failure and denied assistance in covering the cost of the repair. The failure mileage was approximately 136,000.

"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. ".

Whining sound coming from vehicle while in drive and accelerator is depressed. Confirmed by dealership that the transmission is failing and needs replacement.

When pulling into a shopping center parking space, my mother applied the brakes to slow down, but the vehicle seemed to surge and hit the car in front. It then surged again and pushed that car into another. No airbags deployed, and no one was injured, but someone could have been hurt either by the van itself or one of the other 2 vehicles. The dealer is scheduled to look at the vehicle, but stated on the phone that they "hadn't heard of this happening". There were no warning lights showing. My daughter stated that after the impact, she looked at my mother's feet, and her foot was clearly on the brake. I looked on the internet later, and found several threads of people complaining about their Toyota Sienna hybrids doing similar things.

We have started to experience the transmission whine at that is specified in Toyota's csp zjc documentation. We took our vehicle into our local Toyota dealership service center and they confirmed that the whine was a transmission issue and that the only course of action to take would be to replace the transmission. Our vehicle was manufactured in the specified window (manufacture date 10/2016, manufacture data window from the program 7/2016-2/2018), it has the specified transmission model (ua80), we are within the coverage window stated in the support materials (within ten years of first use), we are experiencing the same transmission symptoms described in the program support materials (whining transmission noise), and we have been recommended by our local Toyota service members to replace the transmission. From this information, it appears that we meet the criteria and are suffering the same issues as are referenced in the zjc materials, but our VIN is not included in the program. I believe that is an error and the program should be expanded.

Transmission failure. The dealer confirmed the issue and was repaired at an independent shop. There are no warning lights and only audible sounds that caused us to have it checked out. This appears to be a more widespread problem as Toyota did issue a TSB for a subset of vins of this model year.