AutoUtility currently tracks 69 official NHTSA owner defect complaints for the 2018 Toyota Sienna. Powertrain & Transmission issues are the most frequently reported category, appearing in 18 complaints (26.1% of submitted records). Among these NHTSA complaint records, 5 filings cite a crash, 3 report one or more injuries.
Factual proportion of owner complaints categorized by automotive subsystem in NHTSA records
18 owner complaints submitted to NHTSA ODI for this subsystem.
13 owner complaints submitted to NHTSA ODI for this subsystem.
6 owner complaints submitted to NHTSA ODI for this subsystem.
6 owner complaints submitted to NHTSA ODI for this subsystem.
Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation
"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..."
"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..."
"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..."
"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...."
"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."
Reported defect complaint volume across sibling model years (2015–2026)
| Model Year | NHTSA Complaints | Crash Reports | Safety Recalls | Detailed Report |
|---|---|---|---|---|
| 2015 Toyota Sienna | 230 | 17 | 6 | View 2015 Problems → |
| 2016 Toyota Sienna | 75 | 7 | 5 | View 2016 Problems → |
| 2017 Toyota Sienna | 152 | 13 | 10 | View 2017 Problems → |
| 2018 Toyota Sienna Current Page | 69 | 5 | 7 | Current |
| 2019 Toyota Sienna | 45 | 2 | 7 | View 2019 Problems → |
| 2020 Toyota Sienna | 37 | 0 | 2 | View 2020 Problems → |
| 2021 Toyota Sienna | 37 | 0 | 4 | View 2021 Problems → |
| 2022 Toyota Sienna | 15 | 1 | 4 | View 2022 Problems → |
| 2023 Toyota Sienna | 66 | 8 | 2 | View 2023 Problems → |
| 2024 Toyota Sienna | 65 | 5 | 3 | View 2024 Problems → |
| 2025 Toyota Sienna | 264 | 2 | 5 | View 2025 Problems → |
| 2026 Toyota Sienna | 0 | 0 | 0 | View 2026 Problems → |
Complete distribution of consumer defect reports across all 29 granular NHTSA system and subsystem classifications
| Vehicle Component / System | Total Complaints | Crash Reports | Fire Reports | Injury Entries | Fatality Entries |
|---|---|---|---|---|---|
| Powertrain NHTSA category: POWER TRAIN | 13 | 0 | 0 | 0 | 0 |
| Other / Uncategorized NHTSA category: UNKNOWN OR OTHER | 10 | 0 | 0 | 1 | 0 |
| Fuel & Propulsion System NHTSA category: FUEL/PROPULSION SYSTEM | 7 | 0 | 0 | 0 | 0 |
| Air Bags NHTSA category: AIR BAGS | 4 | 4 | 0 | 5 | 0 |
| Fuel System NHTSA category: FUEL SYSTEM, GASOLINE | 4 | 0 | 0 | 0 | 0 |
| Electrical System NHTSA category: ELECTRICAL SYSTEM | 3 | 0 | 0 | 0 | 0 |
| Structure & Body NHTSA category: STRUCTURE | 3 | 0 | 0 | 0 | 0 |
| Engine NHTSA category: ENGINE | 2 | 0 | 0 | 0 | 0 |
| POWER TRAIN,VEHICLE SPEED CONTROL | 2 | 0 | 0 | 0 | 0 |
| Seats & Restraints NHTSA category: SEATS | 2 | 0 | 0 | 0 | 0 |
| CHILD SEAT | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,AIR BAGS,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,SEATS | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| EQUIPMENT ADAPTIVE/MOBILITY | 1 | 0 | 0 | 0 | 0 |
| EXTERIOR LIGHTING,INTERIOR LIGHTING | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,ENGINE | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,STRUCTURE,SEATS | 1 | 0 | 0 | 0 | 0 |
| POWER TRAIN,VEHICLE SPEED CONTROL,SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
| Service Brakes NHTSA category: SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
| STRUCTURE,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| Suspension NHTSA category: SUSPENSION | 1 | 0 | 0 | 0 | 0 |
| Tires NHTSA category: TIRES | 1 | 0 | 0 | 0 | 0 |
| UNKNOWN OR OTHER,ENGINE,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| Vehicle Speed Control NHTSA category: VEHICLE SPEED CONTROL | 1 | 1 | 0 | 0 | 0 |
| VEHICLE SPEED CONTROL,FUEL/PROPULSION SYSTEM | 1 | 0 | 0 | 0 | 0 |
| Visibility / Glass NHTSA category: VISIBILITY | 1 | 0 | 0 | 0 | 0 |
| Visibility & Wipers NHTSA category: VISIBILITY/WIPER | 1 | 0 | 0 | 0 | 0 |
| Wheels & Hubs NHTSA category: WHEELS | 1 | 0 | 0 | 0 | 0 |
Cross-reference safety recalls, crash test safety ratings, and EPA fuel economy for this model year
Key performance indicators, EPA fuel economy specs, powertrain variants, and summary ratings.
Official recall campaigns, safety defect descriptions, and manufacturer free remedy instructions.
NHTSA 5-Star NCAP crash test results, driver assistance systems, and rollover resistance ratings.
EPA fuel economy ratings, electric range, and annual energy cost benchmarks.
Direct, deterministic answers synthesized from verified United States government databases for the 2018 Toyota Sienna
In official NHTSA consumer records, the most frequently cited issue area for the 2018 Toyota Sienna is Powertrain & Transmission, appearing in 18 records (26.1% of submitted filings).
Secondary reported categories include Fuel & Propulsion System (13) and Electrical System (6).
AutoUtility does not issue subjective reliability scores or commercial ratings. In official United States government records, NHTSA tracks 69 consumer defect complaints and 7 safety recall campaigns for the 2018 Toyota Sienna.
Reviewing documented component complaint distributions, recall remedy notices, and active federal investigations provides an objective, evidence-based view of the vehicle's historical safety and defect record.
Among consumer complaint records on file with NHTSA for the 2018 Toyota Sienna, 5 filings cite a crash, 0 cite smoke or fire, and 3 report one or more injuries.
Incident entries represent consumer descriptions at the time of submission to federal authorities and do not establish mechanical causation or legal liability.
The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database under 49 CFR Part 576.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.