Bulletins


BulletinBulletin dateReplacement BulletinItem no.SummaryAdded
POWER TRAIN
0020404/06/200410007125The proper identification of the 7 solenoids used in the u151e/u151f transmissions. *tt05/26/2004
00703R11/07/200310005656Engine control module (ecm) calibration - shifting enhancement. revised. *tt03/09/2004
0070311/07/20030070310005252Engine control module (ecm) calibration - shifting enhancement. *tt update. *tt02/17/2004
POWER TRAIN - AUTOMATIC TRANSMISSION
TC0020306/10/2003TC0020310005618Whenever an automatic transmission is replaced, overhauled or individual components are replaced, use this procedure to clear engine control module (ecm) learned values to prevent subsequent driveability complaints. revised notice. t-103/08/2004
TC0020306/10/2003TC0020310005619Whenever an automatic transmission is replaced, overhauled or individual components are replaced, use this procedure to clear engine control module (ecm) learned values to prevent subsequent driveability complaints. revised notice. tund03/08/2004
TC0020306/10/200310003361Engine control module (ecm) reset memory function whenever an automatic transmission is replaced, overhauled or individual components are replaced. 00-03 all models. *tt10/16/2003
POWER TRAIN - MANUAL TRANSMISSION
0100412/16/200410011860Transmission shifter may become progressively difficult to move. *tt02/02/2005

Consumer Complaints


Fail datemilesoccurencesPurchase date
POWER TRAIN
03/15/2006
 Power slicing door cable assemblies...... work and then not working on and off... did not file complaint before because children complain not working but when i tried... it works about 4 times in the past. first instance in 2008. //// now not working completely/stuck. the power is working, but lock appear stuck to where the lock button wont unlock so door can not be open by button or manually. ***** the warranty is 120,000 mile for power slicing door cable assemblies .... my car door is completely stuck / wont open now at 142,000.
10/10/2006120000
 Tl* the contact owns a 2004 toyota sienna. the contact stated that while decelerating to 10 mph, the vehicle would stall before accelerating. the contact took the vehicle to the dealer and dealer stated they could not find a problem within the vehicle. the contact then took the vehicle to a local mechanic and the mechanic acknowledged the failure but could not identify the problem. the vehicle was not repaired. the failure mileage was 120,000. the vin was not available.
10/10/2006120000
 Tl- the contact owns a 2004 toyota sienna. the contact stated that while decelerating to 10 mph, the vehicle would stall before accelerating. the contact took the vehicle to the dealer and dealer stated they could not find a problem within the vehicle. the contact then took the vehicle to a local mechanic and the mechanic acknowledged the failure but could not identify the problem. the vehicle was not repaired. the failure mileage was 120,000. the vin was not available. kmj
10/10/2006120000
 Tl-the contact owns a 2004 toyota sienna. the contact stated while slow down to 10 mph the vehicle stalls before accelerating. the contact took the vehicle to the dealer and dealer stated they could not find a problem with the vehicle stalling. the contact took the vehicle to a local mechanic and the mechanic acknowledge the vehicle stalling but could not identify the problem. the contact stated the vehicle was unsafe to drive. the failure mileage was 120,000. jo
03/04/201197145
 Tl-the contact owns a 2004 toyota sienna. upon starting the vehicle the contact was unable to get the vehicle out of park. after repeated attempts the contact was able to shift the vehicle out of park. upon shifting the vehicle out of park an anti lock brake light began illuminating on the dashboard. the vehicle was taken to an authorized dealer where a brake switch and the anti lock braking system were replaced. the failure and current mileages were 97,145. sm.
02/03/2010100001
 I wrote to toyota sept. 7, 2007, concerning an acceleration problem with my 2004 sienna minivan, following many visits to the dealer to evaluate and fix it. the throttle response is delayed, in my case; it lags during initial acceleration from a stop, but more importantly, it lags when immediate acceleration is needed for passing, and accelerating after slowing for a turn. the factory rep who responded to my letter said the dealer would reevaluate the problem. the dealer rep drove the van, experienced the same problem, and concluded it was a quirk of the car, that could not be fixed unless, perhaps, the computer controlling the throttle was replaced. they would not do that unless a recall was ordered, he said. needless to say, i thought that was the final word, until other problems began to surface with the fly by wire system in toyotas. i do believe that the electronic throttle, the throttle position feedback circuit, and related sensors are at fault, all of which are controlled by the computer. i also have other cars with electronic throttles, an accord and a town & country, and neither has that problem. no accidents have been caused by this daily malfunction, as i guess i have adapted my driving style to it, but don't you think there is a systemic problem here? the incident date is a continuing date, beginning during the first year of ownership (2004) up to the present time. *tr
07/15/2004213410005/29/2004
 On 5/29/2004 i purchased my toyota sienna. i started having mysterious lights coming on at all different times. on 7/15/2004, i went out to my car and it wouldn't start. this was the beginning of a nightmare. since then my car has been in the shop at least 6 times for this problem. i have not had my car start at least once a month since i purchased it. i would usually just jump the battery but they could never tell me the reason why it kept on happening. there were times that i couldn't even leave my doors open for 5 minutes without it wearing the battery down. when the battery is checked it is always fine. when the battery is fully charged i have the interior lights turn on for no reason. they have put in a new battery and replaced the jbl audio switch because that had been shown to turn on intermittently and drain the battery/engine. neither of these solutions have worked. they finally told me that my car had too many bells and whistles (which all are factory installed) and that i need to connect to a car charger when i come home or to go on long drives at least once a week. *tr
01/15/2007212/19/2003
 Toyota 2004 le sienna. driving on straight, dry, road about 30-40 mph. vsc suddenly light turned on unexpectedly, followed by loud beeping noise. van appeared to hesitate. can't go more than 40 mph. i was glad that there was no car behide me otherwise there would have been an accident. van was brought into dealer (toyota of palo alto, ca). they found no error code. *nm
01/01/200508/15/2004
 We have a 2004 sienna le awd. the vehicle consistently appears to hesitate for 1-2 seconds when accelerating from a dead stop while depressing the accelerator. there has been no accidents, only some scares when merging or entering into flowing traffic from a stop.
05/30/200350005003/26/2003
 This is an ongoing problem. on our 2004 toyota sienna van, there is a dead spot when attempting to accelerate from a slow coasting condition. the problem does not occur when starting from a completely stopped condition. however, if coasting at approximately 5 - 10 mph, depressing the accelerator pedal yields no response. naturally i tend to depress the accelerator further to overcome whatever inertia is happening, and when the engine/drivetrain finally responds (sometimes several seconds later) there is a pronounced jerk as everything catches. we have had a few situations where competing traffic conditions warranted firm acceleration and were at the mercy of other drivers when our vehicle failed to perform. being in a northern climate, i am also greatly concerned that during icy conditions, the resulting jerk which occurs following the lag will result in breaking traction and subsequent skidding. it should be emphasized that failure to accelerate when necessary is arguably just as dangerous as failure to stop, and the problem needs corrected. thus far, our dealership acknowledges the problem and claims that it's a normal behavior for this drivetrain.
POWER TRAIN - AUTOMATIC TRANSMISSION
08/15/201192000
 After years of dealing with this issue toyota has yet to provide a reason or solution. when traveling at lower speeds the transmission disengages and when you need to accelerate there is a 1 to 2 second delay before the transmission re-engages. toyota made me service the transmission...no help....then they claimed i needed a software update...which they charged me $80 ...to update their software design flaw. still... the transmission has not improved. my only concern is that if i should ever need to accelerate to avoid an accident, my van may not respond in time.
01/15/201160000
 Tl-the contact owns 2004 toyota sienna. the contact stated that while driving approximately 25 mph, the vehicle would not accelerate further. the vehicle was taken to an authorized dealer, where the technicians stated that the transmission fluid needed to be flushed and recalibrated. after the repairs, the failure continued. the vehicle was taken to the dealer a second time and the technicians stated that the transmission needed to be replaced. the vehicle was not repaired. the approximate failure mileage was 60,000. sm.
01/15/201160000
 Tl- the contact owns 2004 toyota sienna. while driving at approximately 25 mph the vehicle would not accelerate. the vehicle was taken to the dealer. the technicians stated the transmission fluid needed to be flushed and recalibrated. after the repairs, the failure continued. the vehicle was taken to the dealer a second time. the technicians stated the transmission needed to be replaced. the vehicle was not repaired. the approximate failure mileage was 60,000. ds
05/15/20057000
 The transmission has a delay when running at low speeds and when having to change gears up or down under a change of load condition; like going uphill or passing. very noticeable when you take your foot off of the gas for a moment, like turning into a street or driveway. the van will jump into a gear like if someone had popped the clutch on a manuel transmission. i have had this problem since i have owned the van. i have taken it the the dealer several times and they always say there nothing wrong. i have had the transmission fluid changed several times but nothing changes. i thought i was the only one having this problem until just now; after reading about how many other have the same issue. i wish toyota would just tell the truth about the vehicles that they make instead of just acting like it is always the customers who is at fault. this will be my last toyota. i have owned three in the past, no more. especially since all of the other things that has happen with their cars lately.
07/03/200477000
 Vsc engages at highway speeds: vehicle alarm sounds, brakes deploy abruptly and unexpectedly, steering pulls, accelerator goes dead (pulse races, adrenaline courses). first complained to dealer after four incidents in first 20k miles: had online testimonials of yaw sensor, steering angle sensor and ecm replacements as possible remedies; dealer rebuffed my complaints, denying service to sensors, and suggested my tires had 'gone square'. i have lived with the condition for a total of seven years. the car now 'goes off' maybe three times per every 20 miles driven, unpredictably and always shockingly. my family refuses to ride in the car. i cannot sell it in good conscience, as the defects cannot be confirmed by the dealer (and apparently therefore do not exist), so there is no way for it to be 'made safe' for a succeeding owner. its remaining $10k+ equity has been nullified by this defect.
05/01/2010175000
 While merging onto a hwy i was leaned forward looking through the side rear view mirror with my right hand beside the seat hanging down. i raised my hand to place it on the stearing wheel and my fingers caught on the shifter. the gear shift slid without resistance into reverse and the transmission shifted to reverse and started trying to go backwards. the transmission is competely wrecked and needs to be replaced. no injuries or damage to other vehicles but was a very close call as a friend was in his truck behind us and almost collided.
07/20/200301
 Toyota 2004 sienna. it's the most dangerous car i ever had, whenever i slow down and tend to accelerate, the car hesitate to go for about 1 to 3 seconds delay. i took it twice to the dealer but did not fix the problem, the third time i went back they denied that it is a problem. it is dangerous specially when you tend to pass a car on a two way road and the car wont accelerate at desired timing. my complain was toyota denies that there is a problem. this problem is an ongoing since i purchased it in 2004 to present. *tr
02/19/2010700001
 I have a 2004 toyota sienna, with only 70,000 miles. i suddenly and intermittently lost power steering. it was not total loss--that i could have handled, but it would come and go, even within a single turn. when i turned the wheel, i could not predict how the car would respond. no accident, fortunately, but a couple of close calls. i drove immediately to a t dealer, and they diagnosed a failed u joint and replaced it today. there had been no prior signs of u joint failure. i wanted to submit this in case others are experiencing similar issues. otherwise, i just consider it an isolated case. thanks. *tr
01/08/2010960001
 2004 toyota sienna xle . when accelerating the van hesitates. have to press the accelerator harder to force a hard downshift. this is very dangerous when a predictable acceleration is needed specially merging highway. *tr
10/10/20081450001
 I always took my 2004 toyota sienna in for maintenance. the maintenance was performed by midas or toyota. i took the vehicle in for brakes august 2008 and was told a timing belt was needed along with driving belt. i was never verbally told of a problem with the transmission. i took the vehicle back in for service to replace the timing belt, driving belt, and thermostat; still no mention of a problem with the transmission. a couple of days later the check engine light came on. when i took the vehicle back to the dealer they told me the transmission was bad and show me the dirt from the transmission. never prior to the last visit did they verbally mention anything about a transmission problem. *tr
09/09/20066300010009/09/2006
 Delay 2-3 seconds when press gas pedal. i though i am the only one have this problem. i hope soon toyota can solve this problem because if i will get into and accident with this van i am going to hire a lawyer to sue the toyota. *tr
09/30/200610009/19/2006
 There is 2 to 3 seconds delay and slight acceleration lag even when taking off from a stop. couple of times i was close to run into accident. *jb
04/24/2003250999903/25/2003
 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. *tr
06/11/200739000106/17/2006
 I've seen other complaints about the transmission being hesitant and the car surging and slowing unexpectedly. i've had these problems, too. the dealership told me i needed a flash to the computer that would give the car a shift enhancement. they said it wasn't part of the powertrain warranty, but then agreed to do it for the $45 i initially paid them to look the car over. it shifts more aggressively now, but it still seems to slow and surge unexpectedly and fails to downshift for acceleration at times. today was my first dangerous situation in which i made a left hand turn right before a curve in the road. just as i was beginning my turn a car appeared and i had to step hard on the accelerator. the car did not respond as quickly as it should have, but i did manage to make it across.
05/15/20041
 Vehicle has had a transmission hesitation problem since we purchased it. the delay consists of a 2-3 second delay before the acceleration kicks in. this occurs when merging, turning or attempting to speed up to avoid collisions/objects. we have reported this problem to the dealer every time we bring it in for maintenance, with no improvement in performance. additionally, under cruise control, the car skips gears unexpectedly and revvs randomly. *tr
12/26/2006250001005/29/2006
 Vehicle hesitates when accelerator is pressed. vehicle 'surges' at times when brake is depressed. similar to other complaints noted in this section, my sienna has a rough transmission, tires occasionally spin out with normal acceleration from a parking lot, toll booth, etc. repeated trips to dealership bring no satisfaction: response from dealer is that vehicle is operating within standards. *nm
01/07/2006208/16/2004
 Toyota sienna 2004, 19,000 miles not even 2 years old. 1. valves making noise when driving up hill at slow speed or when start driving. 2. wind noise is unacceptable. problem begins at the very first day of driving the car. 3. one big knocking noise when the vehicle is moving , only when shift from park to d4 and starting to drive. *ak
08/01/2005111/28/2003
 Transmission hesitation and lurch forward. dealer says this is characteristic of transmission. also, rear ac not cold - dealer says this is normal performance. *jb
10/01/200582485004/27/2005
 Delayed engine power while turning, then sudden surge of power. dealership response is: working as designed - drive-by-wire causes the delay. *nm
08/01/200560010/27/2003
 Vehicle hesitates and lurches forward on acceleration. driver gets jerked forward at an abnormal rate. after acceleration upon leaving a stoped state vehicle does not respond and/or hesitates for a second then lurches forward. dealer has been notified many times and they tell me this is a characteristic with the new fly wheel design in the toyotas. they agree it is not right but tell me there is nothing i can do about it?? as a consumer this in unacceptable. am starting to have neck problems as a result of doing a lot of local in town driving and constantly stopping and starting with being jerked around in my van. even the passengers feel it. i think this is a major safety issues since it can create physical damage to the driver and cause an accident if van does not respond to accelerator when expected too. tires may spin out too when the jerky acceleration occurs.
04/01/2005130001
 Problems with the dunlop run flat tires and the transmission on the 2004 toyota sienna.*mr during a 3000 mile service the technician notice that on or more of the tires was balding. all four tire were replaced. a few day after the 3000 mil maintenance the vehicle would not move because there was no transmission fluid. *nm
08/02/2004285001007/07/2004
 2004 toyota sienna xle van. when accelerating from a coast the van hesitates. have to press the accelerator harder to force a hard downshift. this is very dangerous when a predictable acceleration is needed. it seems like the transmission control gets confused on when to downshift. probably a result of what toyota has to do to keep the mileage rating up. the number of times this happens are to numerous to count. *nm
04/01/2005106/01/2004
 2004 toyota sienna experiencing hesitation when trying to accelerate. *mr the problem would occur when starting to move the vehicle, when the consumers removed his foot and placed it back on the throttle, severe hesitation would occur. *sc
07/16/20043000101/31/2004
 After 5 months of purchasing a 2004 toyota sienna the transmission went out and was replaced. the vehicle continues to lag and lurch.*ak
03/04/20051
 I have a 2004 toyota sienna with a transmission hesitation problem. (a problem toytoa denies but there are thousands of complaints about it to dealers) it is dangerous in snowy conditions as the 2 second hesitation results in a slowing down before an abrupt upshift/power surge that breaks the wheels loose in the snow. this then causes the traction control system to engage. i was stuck repeatedly and in many dangerous conditions in the mountains in an attempt to get to a ski area due to this problem. toyota needs to have some pressure put on them. *ak
12/01/20041510011/02/2003
 There is a slight, but annoying and unsafe, hesitation with the transmission when accelerating from a turn or from stopping. i have brought it back to the dealer for numerous tsb upgrades, including replacing of a new transmission. however, nothing has changed !!!!!!
07/18/20040180
 Vehicle transmission appears to have a significant delay, dead spot or trouble deciding what gear it wants to be in. primarily when accelerating if hesitation or a lifting of the pedal takes place and then gas is applied again the car lurches after hesitation and downshifts jerking the car. this can't possibly be healthy for the vehicle transmission long term as well as other car parts. i have had to change my driving habits to account for the poor design of the transmission. i've registered my complaint w/the dealer and they've checked to see if the latest software was on my vehicle and it was. they also indicated that there have been other complaints of this type. the major concern is long term and if my transmission goes bad 3-5-7-10 years from now, how much of this is actually toyota's fault from poor design but then i have to incur the cost. at a large price tag initially this is not fair to the consumer. *nm
07/01/200403606/06/2004
 When i step on the gas there is a pause. toytota says it's an identified problem with the transmission. when i hit the gas, the car should move!*ak
05/16/200340010005/15/2003
 No throttle response for about 2 seconds, occures all the time, most noticeable on a rolling stop at a yeild sign. several near accidents.*ak
01/04/20048000108/20/2003
 2004 sienna ltd awd has both a hesitation in acceleration and shifting problems if the vehicle is at low speed and then the accelerator is depressed. the engine does not respond to the accelerator pedal then after a delay, can over rev and then engage the transmisson. there have been incidents where it causes dangerous delays in avoiding a potentiao accidant situation. taken the car back and was told that toyota says this is operating according to the design. this is an unsafe situation.*ak
09/06/20042000104/02/2004
 When slowing to make a turn the transmission will on occasion hesatate and then surge. *ak
09/13/2004120004
 While merging onto another lane transmission down shifted on its own. consumer applied the accelerator pedal and vehicle would not accelerate. then, consumer noticed that the rpm gauge registered high on the dashboard. consumer took vehicle to dealer for inspection, and mechanic determined that transmission fluid was leaking from underneath, and needed to be replaced. the other problem could not be duplicated by the mechanic. consumer informed mechanic that this problem recurred and had not been resolved. *ak
04/03/2004104/02/2004
 Hesitation of 2004 toyota sienna xle limited. vehicle has a significant delay in acceleration when applying gas from a slow roll (under 5 mph). this is a recurring problem that is not addressed by toyota.*ak
08/24/200417320304/16/2003
 I could not shift out of park upon starting the engine and the vsc and abs light came on, i had to set and release the emergency brake and the brake pedal randomly then re-attempt to shift out of park which would then enable me to shift into drive or reverse. *ak
07/06/20041
 While approaching a left hand turn off a 4 lane undivided highway i saw a vehicle approaching in the middle most lane with its left turn signal on which i interpreted as a sign that the vehicle was going to make a left turn where i was also turning. but it turned out the turn signal must have just been forgotten about and the vehicle was intending to continue travelling straight. by this time i had already started my turn and was in the path of the oncoming vehicle. when i realized that the vehicle was not going to turn i floored the accelerator to get out of its way. the sienna seemed to slow down violently as all passengers in my sienna lurched forward, and then the transmission finally seemed to kick in after what seemed like a couple of seconds of sitting helplessly in the path of the oncoming vehicle, which had to slam on its brakes to avoid colliding with us. this acceleration hesitation could have been much more dangerous if the other driver had not been driving defensively.*ak
12/15/2003111/15/2003
 Engine idles very fast in cold weather first few minutes. while driving a block to the first stop sign has to apply the brakes very forcefully to get the car to stop. this causes some loss of control , especially on a slight down hill slope during snowy/icy weather. appears to be combination idle, and the automatic transmission.*ak
05/31/200499005008/19/2003
 Vehicle hesitates/fails to move forward in the following mode: after braking, when the vehicle is still moving between 5 to 15 mph, the van does not respond to accelerator pedal input; vehicle hesitates with no movement forward, then shifts hard into first gear and lurches forward. we have had 2 close calls, waiting for the vehicle to respond to accelerator pedal input. also, accelerator pedal has a dead spot. the first half inch of pedal causes no response from vehicle). this dead spot along with the hesitation noted above can result in a 2 second response failure from the vehicle. this situation has put my family in harms way on numerous occasions.*ak
05/08/20046000011/19/2003
 Once, while driving on i-5, on a slight incline in 'd'(overdrive), i slowed the vehicle from 60 mph to around 50 mph because of traffic. the vehicle then seem to slip out of gear, the rpms hit approx. 6000, then the vehicle caught a gear. it repeated this several times. i pulled over and call the dealer. he said to if there were no warning lights, then it's probably ok. the second time we were in 'd' and slowing from about 60mph to 50mph coming into a slight corner. the vehicle repeated the same jerking. i notice that when slowing the rpms dip below 2000-1800 before the slipping occurs. i kept the car above 2000 rpms at higher spends by shifting into '3' when needed. this seem to avoid the problem? we brought the car in to the dealer. i was told what happen is normal operation for the new transmissions in the sienna and highlander? however, losing power and being jerked around did not seem safe. i am bringing it to another dealer on this coming friday.
12111/24/2003
 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. *mr the vehicle only hesitates when downshifting. *nm
11/28/20031000111/01/2003
 2004, toyota sienna xle limited. very sluggish throttle response when cruising, apparently due to very sluggish automatic transmission down shift. no problem when accelerating from a stop. problem is bad enough to cause an accident when the driver expects reasonable throttle response to avoid a collision , such as crossing an intersection. *ak
09/02/20031
 While driving automatic transmission did not shift properly from the lower to higher gear. dealer has inspected vehicle and stated it was running under toyota specifications. *ak
POWER TRAIN - AUTOMATIC TRANSMISSION - CONTROL MODULE (TCM, PCM)
09/06/200630000102/24/2004
 Dt*: the contact stated the vehicle hesitated while pulling out of a parking lot with the accelerator depressed. the vehicle was driven to the dealer who determined the transmission control did not operate correctly. the consumer stated there is a 2-3 second delay in acceleration. when the transmission does activate, it seems to search for a gear and when a gear s found it is usually a low gear which causes the vehicle to lurch into traffic. updated 10/04/06. *jb
08/24/200410008/24/2004
 2004 toyota sienna le. vehicle hesitates when acceleration. there is a big delay before the car gains speed. this is a on going problem. dealer states that the car was made that way and there is nothing that they can do to correct the problem. this hesitation can cause an accident at any time.
POWER TRAIN - AUTOMATIC TRANSMISSION - GEAR POSITION INDICATION (PRNDL)
07/14/20046000112/31/2003
 While vehicle was sitting in consumer's driveway consumer's child knocked the gear shift into drive and vehicle rolled backwards, slamming into a wall across the street. the child was not hurt, but the vehicle and the wall were damaged. vehicle's manual stated that vehicle could not be shifted into gear without a key being in the ignition.*ak
POWER TRAIN - AUTOMATIC TRANSMISSION - LEVER AND LINKAGE - COLUMN SHIFT
05/10/200742000106/17/2006
 My husband noticed the 2004 toyota sienna moving in the driveway and found that the automatic transmission shifted out of park. he then played around with it and found that it can be shifted out of park without depressing the brake. i took it to the local toyota dealership and was told that something broke off inside and would cost around $700 to fix it. they then said that my children must have broken it off swinging from the shifter. i responded that i really didn't think that my children did such a thing and the customer service rep admitted that they're probably not strong enough to break it anyhow. thiswas very dangerous. *ak
POWER TRAIN - AXLE ASSEMBLY
02/15/20056000210/29/2004
 With about 6000 miles showing on the odometer, and children present in the vehicle we suffered from a manufacturing defect; a complete mechanical failure that was life threatening. i was on an on-ramp preparing to enter the freeway when i felt the under carriage of the vehicle slam down. the rear differential disintegrated, and the vehicle was unable to accelerate or be put into gear. with tremendous effort and horrendous noises the vehicle could struggle to move at about 5 mph. once the dealer received the vehicle the toyota representative. appeared within days to inspect, collect, and later analyze the failed parts. the transfer case and rear axel assembly were replaced. we cannot and will not be picking this vehicle up from the dealer due to the unexplained and dangerous events that have occurred.*ak
POWER TRAIN - AXLE HUBS
05/15/20059275205/31/2004
 2004 toyota sienna all wheel drives have a suspension or drivetrain issue that causes tires to wear to chords on inside edges in 10 to 15,000 miles.vehicle came with runflat,bridgestones br380runflats and dealer replaced at 9,000 miles due to severe wear with2256017dunlops,now at 28,000 no tread left inner,and require replacement again after 9 months of driving obviou sly problem is not the manufacter of tire but something in deseign of truck or awd system,toyota should recall,this issue cost approx1400.00 in tires for one set and apparently will only last a year,toyota should be accountable for this tire wear issue issue and either retrfit vehicle a suspension drivetrain fix that will not wear tires,it should be noted that i have 2 of the same vehicle with exact same problem,on both toyota replaced the 1st set of tires at under 11,000 miles and basically said too bad it's not toyota problem by the time 2nd set were worn 10,00 mies later.
POWER TRAIN - DRIVELINE
02/01/2008450001
 While making a sharp left turn, i can hear clunk, clunk from the steering column. dealer says the steering column (rack-pinion) joint is bad, need replacement, not under warranty, will cost 500 to 600 $, not an immediate safety threat , can wait until the noise gets too bad. i am not happy that such things break down at 45,000 miles. *tr
POWER TRAIN - MANUAL TRANSMISSION
02/17/20091
 2004 toyota sienna steering. steering suddenly binds while attempting to turn. very hard to steer at times. hard to control. there is 2 to 3 seconds delay and slight acceleration lag even when taking off from a stop. couple of times i was close to run into accident. *tr
POWER TRAIN - TRANSFER CASE (4-WHEEL DRIVE)
02/15/20056000210/29/2004
 With about 6000 miles showing on the odometer, and children present in the vehicle we suffered from a manufacturing defect; a complete mechanical failure that was life threatening. i was on an on-ramp preparing to enter the freeway when i felt the under carriage of the vehicle slam down. the rear differential disintegrated, and the vehicle was unable to accelerate or be put into gear. with tremendous effort and horrendous noises the vehicle could struggle to move at about 5 mph. once the dealer received the vehicle the toyota representative. appeared within days to inspect, collect, and later analyze the failed parts. the transfer case and rear axel assembly were replaced. we cannot and will not be picking this vehicle up from the dealer due to the unexplained and dangerous events that have occurred.*ak