2018 Toyota Sienna Transmission and drivetrain Problems
- Complaints
- 20about this part
- Share
- 28%of 72 total for the year
- Median mileage
- 35,000miles
- Trend
- RisingComplaints filed in the last 3 full calendar years are at least 25% higher than in the 3 years before.
NHTSA recorded 20 complaints about the transmission and drivetrain of the 2018 Toyota Sienna, 28% of the 72 complaints for this model year. Where a mileage was given, the median is 35,000 miles.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“The van struggles to accelerate. There is no way to turn off eco mode. No button is available. Van struggles to go up hills , excelerate thru intersections and always hunting for gears or stuck in a gear and sounds and acts very heavy on power train end. There is an option to turn off eco light.turning off eco light does nothing but hide the problem. We need an option to complete disable eco mode with update or with a button.”
NHTSA complaint #11170282, filed 2019-01, 4,500 miles“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 complaint #11719964, filed 2026-02“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. …”
NHTSA complaint #11581429, filed 2024-04“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 complaint #11745443, filed 2026-06“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. …”
NHTSA complaint #11708394, filed 2026-01Related service bulletins
- 10201352Jul 6, 2021TT: Some 2014-2021 model year vehicles equipped with Dynamic Torque Control AWD system may experience a ?Noise? or ?Abnormal Operation? condition from the rear differential front…
- 10198131May 11, 2021TSB: Some 2017 ? 2018 model year Highlander and Sienna vehicles may exhibit a whine noise while driving, a harsh shift, MIL ON, or reduced power. The following Diagnostic Trouble…
- 10171406Jan 27, 2020TT: Currently under investigation. Please contact TAS if you have a vehicle that exhibits a leak from the Transmission Side Cover with no signs of damage or other conditions…
- 10169406Nov 4, 2019TT: Some 2018-2020 model year UA80/UB80 transmission equipped models may experience a leak from the Transmission Side Cover. This issue is currently under investigation. Vehicles…
- 10164347Jul 11, 2019Customer Support Program Bulletin: Toyota has received reports indicating potential symptoms, such as a whine noise from the transmission while driving, harsh shifting, reduced…
- 10164330Jul 1, 2019TSB: REVISION NOTICE July 01, 2019 Rev2: ? Applicability has been updated to 2019 ? 2020 model year Toyota vehicles. ? The Techstream Preparation and Process Overview sections…
- 10162233May 1, 2019Customer Support Program Bulletin: Toyota has received reports indicating potential symptoms, such as a whine noise from the transmission while driving, harsh shifting, reduced…
- 10159730Apr 18, 2019Customer Support Program Bulletin: Toyota has received reports indicating potential symptoms, such as a whine noise from the transmission while driving, harsh shifting, reduced…
- 10159729Apr 18, 2019Dealer Packet: Toyota has received reports about potential symptoms, such as a whine noise from the transmission while driving, harsh shifting, reduced power, and master warning…
- 10159728Apr 18, 2019Dealer Email: Toyota has received reports about potential symptoms, such as a whine noise from the transmission while driving, harsh shifting, reduced power, and master warning…
Transmission and drivetrain: other model years
| Year | Complaints | Share of year |
|---|---|---|
| 2022 | 2 | 2% |
| 2021 | 8 | 5% |
| 2020 | 8 | 21% |
| 2019 | 7 | 15% |
| 2018 | 20 | 28% |
| 2017 | 38 | 24% |
| 2016 | 3 | 4% |
| 2015 | 12 | 5% |
| 2014 | 7 | 4% |
| 2013 | 14 | 8% |
| 2012 | 17 | 7% |
| 2011 | 30 | 5% |
| 2010 | 17 | 10% |
| 2009 | 6 | 3% |
| 2008 | 38 | 9% |
| 2007 | 31 | 9% |
| 2006 | 40 | 4% |
| 2005 | 48 | 4% |
| 2004 | 89 | 4% |
| 2003 | 10 | 10% |
| 2002 | 13 | 7% |
| 2001 | 6 | 3% |
| 2000 | 67 | 18% |
| 1999 | 11 | 5% |
| 1998 | 23 | 8% |
Other parts of the 2018 Toyota Sienna
14 complaintsFuel system
13 complaintsElectrical system
7 complaintsAir bags
5 complaintsEngine
5 complaintsBody and structure
5 complaintsVehicle speed control
5 complaintsSeats
4 complaintsBrakes
2 complaintsVisibility (wipers, defrost, mirrors)
2 complaintsEquipment
1 complaintsExterior lighting
1 complaints
← All problems reported for the 2018 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