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What 36 owners told NHTSA about the 2021 Toyota Sienna
These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.
2 of 36 complaints match · Transmission & drivetrain · clear filters
Jun 27, 2026Transmission & drivetrainElectrical systemFuel system
Unexpected failure of the acceleration pedal to accelerate from a complete stop to a go at an intersection. The electric vehicle (EV) motor began accelerating up to about 3 mph than instantly had a failure to accelerate, even with the gas pedal continuously pushed to the floor. After about 4 to 5 seconds the engine kicked on and began accelerating. The failure seemed to occur during the EV motor swapping over to the gas powered engine. This has been the fourth occurrence and can be extremely dangerous at intersections with oncoming traffic. No fault codes or check engine lights came on.
NHTSA ODI 11746943
Feb 11, 2026Transmission & drivetrainBrakesDriver assistance
The car jerks when coming to a stop. Like when the regenerative system is disengaged it jerks. For the Adaptive cruise control the car will accelerate instead of braking when another car merges in front of you.
NHTSA ODI 11717402
Working with the data? Download all 36 complaints as CSV · fetched from NHTSA July 19, 2026
How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your
pre-purchase inspection list. Back to the
full 2021 Toyota Sienna verdict →