The transmission was doing what felt like "neutral drops" at low speeds, where I would shift into drive, get the "clunk" that I normally associate with the transmission dropping into first, then depress the gas slightly to start moving. The problem is that the engine would rev suddenly, and then catch first, which as you know, causes a sudden lurch of the entire vehicle since the engine had been revving just before it caught. It would also occasionally just "lose" the gear while driving at low speeds. On 6/12/2010 the transmission went out on me while I was driving home (with my family) on the fwy (North 5) from legoland. I have to across 5 lanes to get to the shoulder. I got the van brand new on 3/28/2007 (w/only3 miles on the van) from carson Toyota, ca...I paid $28000 w/package3 (out the door price)...as of 6/12/2010 the van has under 14,000miles. The Toyota dealer replaced the transmission with no charge (still under powertrain warranty). Transmissions aren't supposed to go out that quickly, it definitely seems to be a quality control issue. Under 14,000 miles there has been no service due so it's not a matter of missing scheduled maintenance. This is obviously a very valid safety concern.

- Temple City, CA, USA

Purchase a 2007 Toyota Sienna minivan in December 2007 with almost 20,000 mile in it. After purchase notice that when engine is cold it sounds like a diesel engine until it warms up. Also notice what feels like a slip in the transmission in lower gear. This happens if following behind someone and they turn U need to slow down. When U accelerate to get back up to speed there is a delay or a slip before transmission engages, complained with the local dealer (andy mohr Toyota) where purchase from. We have complained since day one of ownership. Toyota dealership states that the vehicle has a memory transmission and learns your driving habits. Well me and my wife don't drive the same and neither does anyone else. No people drive the same and why would someone make a vehicle like this. They also stated that there is no fix at this time. Just trying to blow me off. As for the engine slap when cold they told me it was the exhaust heating up. Now I am no mechanic but let me tell you that is not an exhaust clapping up while heating. Called Toyota usa and file a complaint after a year being pissed at what we spent and how unhappy we were. They set up a third party arbitration and a person from Toyota. We met at the dealership and I voiced my concerns. We even went on a test drive so I could show them what it did. What a joke that was. The person from Toyota explained to me the vehicle was doing exactly what it should be doing. ( the delay in the transmission to me seems to be another Toyota problem that they don't want to acknowledge and im just crazy.) I have never owned a vehicle that did this. I guess we will need for some people to get rearended and killed before something is done about it. Nothing came out of it and now we are stuck with this expensive van that's a heap. Purchased Toyota for there reputation and what a joke. Never again will I do this. I will sure research before I purchase my next vehicle. Toyota's a joke don't buy!!

- Indianapolis, IN, USA

On August 11, 2007, my family experienced a head on collision. We were driving a 2007 Toyota Sienna. My husband was driving and died at the scene. The investigation never found any reason for the cause of the accident. My husband crossed the center line while going round a slight curve. He was 47, poor weather was not issue. If the accelerator on the Sienna malfunctioned and did not respond, that could definitely have been a factor. Our van had less than 3000 miles on it. We purchased in May 11, 2007. The autopsy for my husband came back negative for any medical condition concern. Please investigate our accident report and be sure the safety and reliability of Sienna's is sound. Updated 03/10/10 updated IVOQ 08/24/10 update 9/19/2011

- Rochester, MN, USA

My 2007 Toyota Sienna accelerate on turns or when trying to stop.

- Brookline, MA, USA

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.

- Sarasota, FL, USA

2007 Sienna, hesitates after re-accelerating between 5 to 10 mph. Acceleration pressed but car does not move for 1 or 2 second. Took to dealer 3 time and also talked to Toyota hq (dealer did find problem but hq said not to put anything in report saying there is a problem) they just saying nothing can be done to car right now a.K.a no updates available also automatic transmission has lot of jerks when it switches gears... example: Half stop at stop sign and it accelerates without depressing the pedal and RPM going up but car not moving until half way down to intersection.

- Schaumburg, IL, USA

Transmission slipping on 2007 Toyota Sienna van. When traveling at 6-8 mph the transmission will slip when the accelerator is depressed. The van will hesitate then suddenly lurch forward. The dealer says that this is normal and will not do anything to repair it.

- Clermont, FL, USA

Engine/transmission hesitation/non-responsiveness. This is particularly apparent when you lift off the throttle to go over a bump or turn. When you press the throttle after that, the throttle does not respond quickly like any of my other vehicles. This happens all the time.

- Placentia, CA, USA