38 problems related to automatic transmission have been reported for the 2004 Toyota Sienna. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Toyota Sienna based on all problems reported for the 2004 Sienna.
No throttle response for about 2 seconds, occures all the time, most noticeable on a rolling stop at a yeild sign. Several near accidents.
I own a 2004 Toyota Sienna with a transmission shifting problem that has been occurring since I purchased the new vehicle back in March 2003. This problem is not just on this particular vehicle as I test drove several other new vehicles from the dealer where I purchased this. The problem with the transmission is that it doesn't know when to downshift to a lower gear, particularly between 0-15 mph. When it can't decide to downshift, you can't accelerate at all. This is very dangerous when in an intersection while attempting to make a left hand turn. I made several complaints through the Toyota dealership back in 2003 and 2004. I was told that this is common with this transmission and that Toyota was going to make a software change to fix this. It has not yet been fixed and I see that they now have the same problem with the camry. Are they going to wait until someone gets killed before they do something? action needs to be taken by Toyota to fix this issue with the camry's and Siennas.
Vehicle is having a problem with the transmission. There is a 3 second hesitation interval before the vehicle will move into gear. When driving around town, it is at it's worse. Vehicle is equipped with a 5 speed automatic transmission. The vehicle only hesitates when downshifting.