2018 Toyota Sienna problems & reliability
69 owner complaints filed with NHTSA for the 2018 Toyota Sienna, alongside 7 safety recall campaigns. Last verified Aug 7, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several vehicles.
3 complaints report injuries (6 injured).
Federal crash records (FARS 2020–2023): 2018 Toyota Sienna vehicles were involved in 18 fatal crashes with 4 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Power Train → | 18 | 26% |
| Unknown OR Other | 13 | 19% |
| Fuel/propulsion System | 9 | 13% |
| Electrical System | 6 | 9% |
| Air Bags | 5 | 7% |
| Engine | 5 | 7% |
| Structure | 5 | 7% |
| Vehicle Speed Control | 5 | 7% |
| Fuel System, Gasoline | 4 | 6% |
| Seats | 4 | 6% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Mileage when problems occurred
Half of the failures with a reported odometer reading occurred by 30,000 miles (middle 50% between 6,684 and 55,500 miles), based on 35 complaints that included mileage.
Complaints by incident year
What owners report
“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…”
Power Train · filed Jul 14, 2026
“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…”
Power Train · filed Jun 21, 2026
“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…”
Power Train · filed Feb 23, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Technical service bulletins
300 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2018 Toyota Sienna. The 10 most recent:
OBSOLETE NOTICE January 30, 2026: This bulletin is now obsolete. Please see T-SB-0001-26.
T-SB-0106-22 Rev2 · Service Bulletin/Repair Instructions · issued Jan 30, 2026
Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software.
T-SB-0001-26 · Service Bulletin/Repair Instructions · issued Jan 28, 2026
Some 2005 – 2026 Toyota vehicles that have undergone water intrusion may exhibit a condition in which a musty odor is present. Follow the procedures in this bulletin to remediate the odor and address this condition. The…
T-SB-0055-24 Rev2 · Service Bulletin/Repair Instructions · issued Jan 7, 2026
Some customers may experience echoing on the line calling the vehicle when using Bluetooth Hands Free. This is caused by the phone Hands Free volume being too low.
T-TT-0790-25 · Service Bulletin/Repair Instructions · issued Aug 20, 2025
The air conditioning dye injection tool kit has been developed to aid in identifying the location of air conditioning refrigerant leaks. The procedures outlined in this Service Bulletin aid in locating, inspecting, and…
T-SB-0058-23 Rev1 · Service Campaign · issued Jun 13, 2025
To assist with the early detection and early resolution of audio related concerns you may be asked to recover MMR data from the head unit. The following steps are instructions on how to retrieve the data from the system…
T-TT-0780-25 · Service Bulletin/Repair Instructions · issued Apr 2, 2025
To assist with the early detection and early resolution of audio related concerns you may be asked to recover MMR data from the head unit. The following steps are instructions on how to retrieve the data from the system…
T-TT-0780-25 · Service Bulletin/Repair Instructions · issued Apr 2, 2025
Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software…
T-SB-0106-22 Rev2 · Service Bulletin/Repair Instructions · issued Feb 11, 2025
Some 2018 – 2024 model year Toyota vehicles equipped with a Premium Audio with Dynamic Navigation System require a Special Service Tool (SST) USB flash drive to update the map, points of interest, and system software…
T-SB-0106-22 Rev2 · Service Bulletin/Repair Instructions · issued Feb 11, 2025
The condition known as acid rain is caused by airborne chemicals or particles in the atmosphere, which mix with rainwater, nighttime dew, or high humidity to form acidic compounds. If these contaminants settle and…
T-SB-0039-24 Rev2 · Service Bulletin/Repair Instructions · issued Dec 6, 2024
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2018 Toyota Sienna has 7 NHTSA recall campaigns — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2018 Toyota Sienna?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.
- · Owners most often reported problems around 30,000 miles — budget accordingly if the car is approaching that mileage.