Two problems related to transmission not engage have been reported for the 2007 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Toyota Sienna based on all problems reported for the 2007 Sienna.
On mon 10/22/2012 at 11:15 am I experienced sudden uncontrolled acceleration driving my van. I was traveling on I-696e in detroit at a constant 70mph, then slowed to 45mph due to construction. As traffic cleared the construction, I pushed the accelerator pedal to pass a semi-truck. I felt the accelerator continue to depress, I completely pulled my foot off but the pedal did not come back nor did the vehicle slow down. Rather, it did just the opposite and continued to accelerate. I attempted to brake hard with no response--the vehicle did not slow down. Then I put the van in neutral to slow down the engine with no results, the van continued increasing 60+mph with no foot on accelerator. This is when I became extremely frightened. The vehicle was pulling from side to side. I looked down to see if there was any interference from the floor mat and none was seen. I tapped gas pedal - no response. Next I put van back in drive and braked --no response again. Then I downshifted to 4th, the engine did not slow, and further downshifted to 3rd gear. Finally, the engine responded and slowed. I used the gas pedal cautiously as I then shifted to 4th so that I could exit the freeway. I parked at my office & immediately called my husband first and explained what happened and I then immediately called the our Toyota suburban dealer. They told me to bring it in for inspection. I was still shaking when I brought the vehicle in and extremely upset. After two inspections, they stated sudden acceleration was caused by the floor mat. Although this seems reasonable, it does not explain why brakes failed to overcome the engine, and shifting to neutral failed to disengage the transmission. The vehicle scares me to death. I do not know what to do next. I consider myself a serious witness as a registered nurse (rn/bsn) with 20 yr manual driving. Ref Toyota case #[xxx] and #[xxx]. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).
2007 Toyota Sienna: transmission temporarily fails to engage the correct gear after decelerating then re-accelerating resulting in a pause or hesitation before control is again regained. This occurs most frequently when slowing for turns at intersections or behind slowing traffic or attempting a lane change. Three service calls have been made on the vehicle which were recorded as a "bad ecu program". Service technicians "reprogrammed the ecu" to "reset adaptive memory and shift points" however there was no change in performance. It was suggested that this was a design problem which had been corrected in later model years. The potential consequences of the transmission's failure to immediately engage in the correct gear are the loss in ability to quickly accelerate out of a pending collision or to avoid slowing in the middle of an intersection and causing others to have collisions.