2,542 problems have been reported for the 2004 Toyota Sienna. The following chart shows the 26 most common problems for 2004 Toyota Sienna. The number one most common problem is related to the vehicle's structure with 904 problems. The second most common problem is related to the vehicle's latches/locks/linkages (302 problems).
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 2004 Toyota Sienna in the United States are 220,314 units [1]. If the total number of problems reported by Toyota Sienna owners in the last 21 years is 2542, and the age of the vehicle is 21, the PPMY index can then be calculated as
PPMY Index = 2542 / 220,314 / 21 * 1000 = 0.55.
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 2004 Toyota Sienna in 2004.
| Service Year | Number of Problems |
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When making the decision between buying a new or used Toyota Sienna, the following table can be used to compare the 2004 Toyota Sienna with the Toyota Sienna from other model years. Note that the number of problems reported for the 2004 Sienna is 2,542 while the average number of problems reported for the 30 model years of the Toyota Sienna is 366.