There are 6 owner-reported powertrain & transmission complaints for the 2015 Toyota Siennain NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
The contact owns a 2015 Toyota Sienna. The contact stated that while the vehicle was parked, and the shifter lever was turned off, it unexpectedly fell down, causing the vehicle to shift into drive and roll down the street, where it crashed into a house. At the time of the incident, the vehicle was occupied by one three-year-old and two six-year-old children. One of the six-year-old occupants attempted to move the shifter into park while another attempted to steer the vehicle. The passenger-side sliding door was ajar. There were no warning lights illuminated. There were no reported injuries, fire, or airbag deployment. A police report was filed. The vehicle was taken to a local dealer; however, the failure was not diagnosed or repaired. The manufacturer was contacted, but declined the claim. The failure mileage was approximately 119,274.
My husband parked our minivan and came in to pick up the kids. While he was inside the library, the van went out of park and hit a fire truck in the parking lot. It seems this has been an issue with Toyota siennas in the past but I do not see it reported yet for its year 2015. Our van had damage to the front fender, hood, and surrounding area and needed repair. We obviously didn’t have any idea this was possible nor noticed anything since purchasing this van recently. I have read online that a Toyota sienna cannot be turned off without being in park. Since my husband was not in the vehicle when it crashed in the parking lot, it is clearly a defect of the vehicle.
MY SIENNA VAN SOMETIMES RESPONDS VERY LATE TO ACCELERATION. THIS BECOMES A PROBLEM ON HIGHWAYS SPECIFICALLY DURING THE MERGING. ACCELERATION PADDLE HAS TO BE PRESSED VERY HARD, FOR FIRST FEW SECONDS THERE IS NO RESPONSE FROM ENGINE THEN LATTER IT SUDDENLY ACCELERATES. THIS MAKES YOU MISS JUDGE THE TIME REQUIRED TO MERGE ON HIGHWAYS AND CAN CAUSE ACCIDENTS. THIS HAS BEEN HAPPENING SINCE FEW MONTHS. I AM PROVIDING TENTATIVE DATE BELOW.
TL* THE CONTACT OWNS A 2015 TOYOTA SIENNA. AFTER THE CONTACT PLACED THE GEAR IN PARK, SHE COULD NOT SHIFT OUT OF THE PARK POSITION. THE CONTACT SHUT OFF THE VEHICLE AND IT WOULD NOT RESTART. IN ADDITION, THE BRAKE OVERRIDE MALFUNCTION INDICATOR ILLUMINATED AND "VISIT YOUR DEALER" APPEARED ON THE INSTRUMENT PANEL. THE VEHICLE WAS TOWED TO POWAY TOYOTA (13631 POWAY RD, POWAY, CA 92064, (858) 486-2900) TO BE DIAGNOSED, BUT THE RESULTS WERE PENDING. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 72,043.
WHEN AMBIENT TEMP IS BELOW FREEZING AND VEHICLE IS COLD THE ENGINE REVS UP FROM BELOW 1000 RPM TO NEARLY 1500 RPM WHEN COMING TO A STOP AND THE VEHICLE WANTS TO LURCH FORWARD. I MUST BE ON THE BRAKE TO PREVENT LURCHING FORWARD. IT REVS UP AS THE TRANSMISSION IS DOWNSHIFTING. DEALER SAYS IT IS NORMAL. THIS IS NONSENSE.
TL* THE CONTACT OWNS A 2015 TOYOTA SIENNA. THE CONTACT STATED THAT THE VEHICLE WAS NOT DRIVING NORMALLY AND IT FELT AS IF THE TRANSMISSION WERE FAILING. THE VEHICLE WAS TAKEN TO THE DEALER WHERE IT WAS DIAGNOSED THAT THE TRANSMISSION FAILED DUE TO A MINOR CRASH IN WHICH THE CONTACT WAS INVOLVED. THE TRANSMISSION WOULD NEED TO BE REPLACED. THE VEHICLE WAS REPAIRED. THE MANUFACTURER WAS INFORMED OF THE FAILURE. THE APPROXIMATE FAILURE MILEAGE WAS 7,000. THE VIN WAS NOT AVAILABLE.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026