48 problems have been reported for the 2020 Toyota Sienna. The following chart shows the 15 most common problems for 2020 Toyota Sienna. The number one most common problem is related to the vehicle's power train with 8 problems. The second most common problem is related to the vehicle's engine and engine cooling (6 problems).
| Problem Category | Number of Problems |
|---|---|
| Power Train | |
| Engine And Engine Cooling | |
| Electrical System | |
| Equipment | |
| Other Fuel System | |
| Structure | |
| Steering | |
| Gasoline Fuel System | |
| Service Brakes | |
| Visibility | |
| Air Brake | |
| Wheel | |
| Electronic Stability Control | |
| Air Bag | |
| Seats |
In our research we use the PPMY index to compare the reliability of vehicles. The PPMY index of a certain model is defined as the problems reported per thousand vehicles per Year. The total sales of the 2020 Toyota Sienna in the United States are 66,242 units [1]. If the total number of problems reported by Toyota Sienna owners in the last 6 years is 48, and the age of the vehicle is 6, the PPMY index can then be calculated as
PPMY Index = 48 / 66,242 / 6 * 1000 = 0.12.
For more information, refer to this page: A study of reliability comparison across Toyota Sienna model year vehicles.
The following chart shows the number of problems reported during each of the service years since the debut of the 2020 Toyota Sienna in 2020.
| Service Year | Number of Problems |
|---|---|
| 2026 | |
| 2025 | |
| 2024 | |
| 2023 | |
| 2022 | |
| 2021 | |
| 2020 |
When making the decision between buying a new or used Toyota Sienna, the following table can be used to compare the 2020 Toyota Sienna with the Toyota Sienna from other model years. Note that the number of problems reported for the 2020 Sienna is 48 while the average number of problems reported for the 30 model years of the Toyota Sienna is 372.