What 69 owners told NHTSA about the 2018 Toyota Sienna

Vehicle: 2018 Toyota Sienna XLE AWD, VIN [XXX], approximately 112,000 miles. Component: Power Train / Automatic Transmission (UA80F 8-speed). The vehicle has developed a pronounced whining noise from the transmission that rises with road speed, accompanied by harsh/rough shifting. A Toyota dealer inspected the vehicle and diagnosed a failing transmission requiring replacement. The symptoms and diagnostic trouble codes match those described in Toyota TSB T-SB-0160-18 ("Transaxle Whine Noise, Harsh Shift, MIL ON, or Reduced Power") for the UA80 8-speed transmission. This is the same failure mode Toyota acknowledged in Customer Support Program ZJC, which attributes the defect to a washer/locking tab that was not sufficiently bent during assembly, allowing an internal nut to loosen and causing progressive internal damage. However, this vehicle's transaxle serial number falls outside the range covered by ZJC, so Toyota has not provided coverage despite the identical defect and symptoms. This represents a safety concern. Based on documented failures of this transmission across the UA80 platform, the condition can progress to loss of power, limp mode, or sudden loss of forward propulsion while driving — including at highway speed and without further warning — creating a risk of a crash or of being stranded in traffic. The vehicle has been maintained through authorized Toyota service. I am requesting that NHTSA investigate whether the UA80/UA80F transmission defect warrants a broader safety defect determination and recall, given the volume of similar complaints across affected model years INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11750202

Since owning my 2018 Toyota Sienna, I have experienced hesitation and erratic shifting with my transmission. I have the UA80E transmission which upon research others are experiencing issues with as well. It appears Toyota is not fully acknowledging the problem. The problem is a safety issue as sometimes when you go to quickly accelerate (merging, making a turn while starting from a stop, etc) the transmission hesitates and doesn't engage for a few seconds. This is an ongoing problem with the transmission. Toyota really needs to fix these transmissions!

NHTSA ODI 11745443

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.

NHTSA ODI 11719964

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.

NHTSA ODI 11715126

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.

NHTSA ODI 11711540

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.

NHTSA ODI 11708394

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.

NHTSA ODI 11678376

Hi, I’d like to report a serious issue with my 2018 Toyota Sienna related to the recent fuel system recall. Since the repair, the vehicle has leaked all of its gasoline not once, but three separate times. One of those times, my family was inside the vehicle, and the smell of gas was overwhelming. The car wouldn’t start, and it was clearly an unsafe situation. Now the dealership is charging me $1,400 to replace the fuel pressure hose and clamp, which, after thorough research and review, appears to be directly related to the process they followed when replacing the recalled fuel pump. I’ve also tried contacting the service manager, but I haven’t received a call back. That’s why I’m now requesting that Toyota open a formal case to investigate this properly. I believe this repair should be covered, and I’m asking for support from Toyota directly.

NHTSA ODI 11672868

Odometer Fraud. The contact purchased a 2018 Toyota Sienna. The contact stated that while attempting to register the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 57,000, and at the time of registration, it was discovered that the mileage was 175,152.

NHTSA ODI 11664914

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

NHTSA ODI 11656942

Power Sliding Door Cable broke but not covered on current service bulletin POL19-02 dated 06/19/2019 The door affected is the passenger sliding door on the drivers side of the vehicle.

NHTSA ODI 11643183

The contact owns a 2018 Toyota Sienna. The contact stated while driving at an undisclosed speed, the vehicle jerked and lost motive power. In addition, the contact stated that on several occasions the vehicle shut off independently. The vehicle was taken to the dealer; however, the failure could not be duplicated. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. In addition, the contact stated that the vehicle was taken to the dealer several times due to the failure. The contact stated that the failure began in 2019 but had become a persistent failure. The contact stated the vehicle was repaired under of an unknown recall and the fuel pump was replaced in 2020; however, the failure reoccurred. The manufacturer was not made aware of the failure. The failure mileage was unknown.

NHTSA ODI 11613601

This is a reoccurring issue on numerous occasions but the transmission programming is a danger to drivers when it is in economy mode (the default setting when car starts up). The transmission constantly starts at a higher gear (3rd or 4th) and reduces throttle input from a stop. It makes for a slower takeoff when making a right turn on the stop sign because the engine would be lugging. Similarly when trying to overtake or merge lanes and you try to speed up the vehicle, the car does not want to downshift. The above mentioned problems are not there when eco-mode is disabled or the car is put into sport mode.

NHTSA ODI 11605484

The contact owned a 2018 Toyota Sienna The contact stated while driving 70 MPH, the contact was rear-ended and the vehicle lost control and the vehicle rolled over multiple times and fell into a ditch. The contact stated that the side air bags did deploy but the front air bags did not deploy vduring the accident. Medical attention was given to the contact and her family in which they were transported to the local emergency room. The contact stated she and her family suffered injuries the contact stated she had bruised ribs a contusion to her hip and her shoulder and a bruised lung. The contact daughter suffered a concussion neck and shoulder and was diagnosed with manubrium in her back. The contact son suffered a concussion contusion on his abdomen and neck. The contact spouse suffered an injured wrist finger injury and possibly broken ribs and all of the family suffered from whiplash. A police report was filed. The vehicle was towed to a local towing company and the vehicle was released to the insurance to be sent to CO-part. The dealer was contacted and the vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 117,000.

NHTSA ODI 11596860

The contact owns a 2018 Toyota Sierra equipped with a Joysceer USA Inc, Hand Control Unit. The contact stated that while operating the vehicle, the message advising to "Stop immediately" was displayed with the error code: 4209 BSM. The contact stated that later a second error code: 1069 SAM was displayed. The contact stated that the messages were due to a malfunction of the Hand Control Unit. The cause of the failures was not yet determined. The manufacturer and installation facility were contacted regarding the failure, but no response was provided. No identifying information was available for the equipment. The failure mileage was 2,000.

NHTSA ODI 11594383

There has been a "whining" noise or "hum" upon acceleration noticed for several months to a year, could be longer, but getting worse over time. There is also a delay when pressing on gas for the vehicle to actually accelerate. I have had many instances where I am almost hit from behind because of this delay. Obviously the person's behind me have been following me entirely too closely, but nonetheless, scary. This is our primary vehicle for our family, which carries 4 precious boys. I am aware of the CSP already in place for this issue but have been told that my specific vehicle does not qualify for the customer protection program. That seems very odd given the amount of vehicle's listed as "affected"(83,700) sienna's and 66,500 highlanders. You cannot tell me that there are not more out there like mine that are having the SAME problems but being told "not covered". I do not think anyone should have to drive a vehicle with children in it that you are unsure when your transmission is just going to go out or fear getting hit from behind because of the delay in acceleration. Please please do something about this in order to hold toyota accountable!

NHTSA ODI 11581429

I am an owner of a 2018 Toyota Sienna LE. The Vehicle has an issue with the safety connect system. Dealer first states that the cause is the data handling being off, called Toyota turned it on and waited for a few days and still did not work. Called Dealer to make an appointment for service, dealer advised that they reset the DCM twice and to wait 24-48 hours to see if it works. It still does not work. No lights present on the overheard place where the SOS Safety connect Button is located.

NHTSA ODI 11573570

When accelerating, both from a stop and/or at speed, there is a definite hesitation. When gas pedal is pressed down, there is a noticeable pause before acceleration begins. This causes safety issues especially when accelerating to merge with moving traffic. Have owned this van since Oct 2021, and it has always been an issue. Possible fuel filter problem. Have not reported issue to dealer. Currently under extended warranty.

NHTSA ODI 11566964

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NHTSA ODI 11542457

The contact owns a 2018 Toyota Sienna. The contact stated that while driving at approximately 70 MPH, the sunroof glass exploded without impact while closed. No warning lights were illuminated. The vehicle was taken to a local dealer, where it was diagnosed that the sunroof glass needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was 58,634.

NHTSA ODI 11517457

The contact owns a 2018 Toyota Sienna. The contact stated while driving at an undisclosed speed, the vehicle hesitated while accelerating. Several unknown warning lights were illuminated. Additionally, the "Pull Over - Take to Dealer" message was displayed. The vehicle was taken to the dealer, where it was determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure and confirmed that the VIN was not included in Customer Support Program: ZJC (Coverage for UA80 Transmission). The failure mileage was approximately 132,000.

NHTSA ODI 11513668

The fuel line under the intake ruptured when I started my car on 2/21/23. The repair shop said they had never seen one fail like this. I do not have the parts. I was fortunate to be at home and that the engine wasn't hot when this happened so there was no fire. I had an issue starting the car ~ 1 month before that, but I don't know if the issue was fuel related. The car had been sitting for 1 week prior to that issue.

NHTSA ODI 11509440

Car stalled, sputtered and died. At first, I thought I was out of gas. After several tries, the car started and went 3 miles to gas station. After getting gas, the car wouldn’t start several times and that same day the check engine light came on. We took it to Autozone to check the code and they said it was showing fuel pump failure. Today I’m taking it in to the dealer for service. It has started and run twice since the initial episode.

NHTSA ODI 11474649

The contact owns a Baby Trend car seat, Model Number: CS661232H-SB-00137, Manufactured Date: 07/05/2021, installed in a 2018 Toyota Sienna. The contact stated that the buckle handle on the left was hard to operate. The contact also stated that the harness connection was defective. The manufacturer was notified of the failure and informed the contact to send the car seat back; however, the contact stated she needed a temporary replacement car seat. The car seat was not repaired nor replaced.

NHTSA ODI 11465804

The last week of September 2021 my husband notice a sound like water runing and a leak on the driver and passenger seats, we take the vehicle to the Dealer for an inspection on October 2nd. They said the AC hose was clogged for a spiderweb and the leak can create a mold. This mold can affect my family health. We informed to the insurance and we taked the vehicle to the Dealer for repair. They did an expensive special cleaning to Remove the mold, and disamble my entire vehicle, the worse is my vehicle still unassembled after 3 months at the dealership. All this happens with out any warning sign, symptoms or light. This vehicle is 3 years old and all services on time and by the same Dealership. My vehicle has a lot of technology but not warning about this AC clogged and damage my entire vehicle wich still on repair.

NHTSA ODI 11448917