Problems with 2004 Toyota Sienna ELECTRONIC STABILITY CONTROL

While driving at or below the speed limit, under dry conditions, on curvy roads, the vsc dash light comes on and engages with beeping and automatic braking. the rapid deceleration and skidding, as the tires lock-up, makes control of the vehicle difficult and cars following must panic brake to avoid rear-ending my vehicle. increasing occurrences over the past year.

When driving under normal conditions the vehicles' vsc will engage. the dashboard lights go off, there is a loud interior beeping sound, the abs engages, the car slows down drastically at once. the roads are dry. at first this happened while driving normal speed exiting or entering an hwy off/on ramp. then happened yesterday as i was driving on neighborhood streets at about 25-30 mph. i could hear a rubbing on the back tires as if the brakes were on.

Traction control all of a sudden started turning on at every turn automatically making the car lock its brakes i'm pretty sure this is not the first you guys have heard of this

The anti skid control light comes on from time to time when i am driving, especially on the highway. in addition to the light, there is warning beeping, as if i'm sliding on ice. at the same time, i completely lose control of the acceleration and braking. it's very scary, and i am concerned for my safety and my family's. this has happened multiple times on clear, dry days, so it's definitely not caused by the road being wet or icy.

When on a curve the traction control engages affecting the brakes and steering of the vehicle. speed does not seem to matter, it has engaged at 10mph and at 65 mph. last straw was when it engaged on the straight away on the highway at 65mph in the high speed lane dropping the speed down to 35mph almost causing a serious accident. it's been happening for a couple of months and two independent mechanics were not able to figure out the problem even after running a moving vehicle diagnostic. it went off a total of 18 times in a aproximate 15 minute, three mile drive with the mechanic. after watching many videos, and complaints online, why hasn't something been done on this issue that has been going on for over eight years now? i'm afraid to take this vehicle on the highway anymore!!!

Traction control malfunction. while driving on curvy roads there is a beeping alarm, steering locks up, brakes engage. the car seems to think that the traction is off. this has been a problem for over a year. no problems driving in city. only happens on curvy roads.

The anti-skid control engaged when turning slightly on the freeway. when it engaged at highway speed (roughly 55mph) it pulled me into oncoming traffic. this is a known problem with this vehicle that should have been recalled.

The anti skid control light comes on from time to time when i am driving, especially on the highway. in addition to the light, there is warning beeping, as if i'm sliding on ice. at the same time, i completely lose control of the acceleration and braking. it's very scary, and i am concerned for my safety and my family's. this has happened multiple times on clear, dry days, so it's definitely not caused by the road being wet or icy.

I have a 2004 sienna with ~125,000 miles on itand this problem has been going on for about 2 months. it happened twice in a span of 5 minutes, and then didn; since then it has occurred with greater frequency and intermittent severity. in almost all cases, it occurs when driving 55-70 mph and while going around a right hand bend in the road, the "skid" light will come on, beep, and then the brakes will suddenly engage, causing the car to pull one way or the other (often left towards oncoming traffic). as soon as you exit the curve, the light goes off and you can accelerate back to speed.

Tl* the contact owns a 2004 toyota sienna. while driving approximately 50 mph, the traction control warning indicator illuminated and a warning chime sounded. the vehicle lost steering and braking ability, and the steering wheel started to jerk from left to right. the contact continued to drive and the failures went away after thirty seconds. the contact stated that the failures randomly started approximately one year ago and grew worse. the contact also mentioned that the lock on the sliding door showed that it was unlocked; however, no one could exit the vehicle when attempting to open the door from the inside or the outside. the vehicle was not taken to a dealer or an independent mechanic for diagnostic testing. the manufacturer was notified of the failures. the vehicle was not repaired. the approximate failure mileage was 150,000.

When traveling at highway speeds and usually on a slight curve to the right, the traction control alarm and breaks go off causing the van to jerk and shake. we have been told this might be low tire pressure but the tires are fine. we have had an alignment, new tires this problem happens randomly and we have not been able to reproduce it for the mechanic. we have been dealing with this for a couple of years maybe happening 20 times. i feel it is just not safe enough to drive or pass this problem on to someone else. i wouldn't want the car on the road with me either i have read online of other toyota sienna's with the same exact problem. this is not isolated and is a safety concern.

Knock sensor and vsc are malefunctioning.

Driving on a dry straightaway highway traveling 67mph and skid light starts blinking with chime sound and van starts breaking and jerking to left alomost getting rear ended by tailgater..

Traction control beeps and brakes hard at unnecessary times, even on freeway on ramps, endangering the occupants and other cars. repeated trips to mechanics have failed to cure the problem. this has been going on for several years and occurs every day.

For no reason the vsc and traction alarm goes off the vehicle brakes on its own dangerously. it is happening daily. usually when going high speed and around a left bend. i went and had the system reset as is called for after alignment. that didn't fix it. i had the steering angle sensor replaced and that didn't fix it. the yaw replaced and that didn't fix it. so now what? this is dangerous for my family.

I am having a massive problem with my vsc. randomly, regardless of speeds (it's happened going 70 as well as 25, and 40 mph), my vsc will kick on, kill my speed, and cause me to swerve. as you can imagine, going 70 on an interstate with other vehicles around and having this happen is life threatening not only to me and my family but other vehicles around me. reading on several auto forums, this problem has been drawn to the attention of toyota corporate to no avail. it is absolutely beyond me that they see no reason to file a recall.

When i drive my van the vsc and trac off lights come on intermittently and cause the vehicle to bog down and pull towards oncoming traffic. i took my van to the dealership and they suggested replacing the steering sensor. we replaced the sensor and the problem persists. with no codes coming up they say they can't fix my van. it happens while driving around corners at 35 mph mostly but has also happened a few times on the freeway at 70. all times it has happened so far has been on dry pavement. toyota doesn't seem to think that there is really a problem since no codes are coming up on their code reader. due to the frequency of the issue i am having it could be disastrous and end up in a head-on collision. how come this vehicle hasn't been recalled. i have included a photo of my service report from the dealership. also there are multiple complaints in different forums regarding this same issue and as far as i have read there is really no resolving it.

Traction-control malfunction during speeds over 40. vehicle traction control engages, at any time and suddenly. abrupt braking and warning light.

Traction control kicks in for no reason, tration beeping and tires lock,at freway speed traction control activates and cuts off speed dramatically.very unsafe to drive.

While driving at 55 mph or faster, generally on a right hand bend, the vsc will activate pulsing the brake and violently pulling the car to the left and towards oncoming traffic. the skid light goes on, and the car beeps until you are out of the turn and then it goes away. this problem has been intermittent for about 6 months but has gotten much worse and more frequent in the previous 2 months. it has been to the dealership several times and they do not know what to do. there are no error codes. the best they can say is "you're going to fast..." which is a wholly unacceptable answer considering we are going the speed of traffic and no more than 0-10 over the speed limit. *tr

I just bought a 2004 toyota sienna xle. when driving the vehicle home i experienced the vsc (traction control system) go off with the dash light illuminating, audible tone beeping and brakes automatically applied all while on dry clean road. the first incident i was making a slight right turn to get on an onramp to the freeway. i was traveling at approximately 35mph when the vsc was activated and caused me to veer hard right and almost hit the right onramp rail. the second time i was getting off the freeway i made a slight right turn at about 30mph and the vehicle veered right from the left lane to the middle of the right lane. i took the vehicle to my mechanic and said that he ran diagnostics on the vehicle and there is no error codes in the computer and does not know what the issue is. mileage is 125,600

The vsc traction control system activates on it's own. driving the van it automatically comes on and brakes the van, dashboard light and beeping noise comes on. brakes you automatically causing the van to veer to the right. this malfunctioning devise with the yaw system is continuing after many trips to the local toyota dealer. they currently have the van and are replacing part after part and the problem still persists. contacted toyota headquarters and filed a complaint with them but they say there is no recall on this van. checked on line and found many other toyota sienna owners who are experiencing the same issues as we are. this is a dangerous safety hazard which can cause an accident. as of today's writing the problem has not been diagnosed by toyota.

When turning in a slight curve on dry surfaces the anti skid control mechanism is activated and the car begins to turn a hard right, it begins to automatically slow down and the internal beeping sound is activated. it is very hard to control the van when it happens and with the automatic slowing of the vehicle if we on a highway i fear we will be rear ended. the internet is full of other 2004 sienna van owners experiencing the exact same issue. it is very dangerous and scary.

My family and i were traveling on the highway at approximately 70 mph when the traction control/vehicle stability control activated causing a beeping sound along with the dash icon blinking. this in turn locked up the left front tire. the van violently swerved to the left and i luckily gained control and pulled to the side of the highway. i thought i had just experienced a tire blow out, but to my surprise nothing was amiss. my wife was distraught at what had just occurred considering the consequences if a vehicle had been next to us at the time. now, driving much slower and white-knuckling the steering wheel, we proceeded to the nearest toyota dealer which was roughly 20 miles away in asheville, nc. along the way, the incident occurred two more times. keep in mind that the skies were sunny and the road dry. arriving at the dealership we waited while the car was looked over. after five hours we were told they could not find anything wrong. i did not accept this and told them that i found hundreds (if not more) of postings on the internet with people having the same incident. i also informed them that toyota had redesigned the steering angle sensor (yaw) in 2005 and asked if that could be the problem. the service writer excused himself and twenty minutes later returned with a toyota service bulletin referring to the sensor. they then ordered the new sensor and we rented a car to continue our trip. returning five days later to pick up the van, we were told the new sensor was installed and a zero point calibration/alignment performed. i paid the $692.00 and drove away. my wife and son stayed in the rental car, since the a/c had mysteriously stopped working when the initial incident occurred. while following them home, the traction control/vsc activated a total of four more times. no one knows how to fix this problem. toyota should recall and fix this.

The vsc sensor is activating during normal driving conditions without warning. this is causing the van to aggressively apply the brakes and lose acceleration. this issue mainly occurs when turning down while going down hill, however it happens randomly in other instances as well. i have been in several life threatening instances where the brakes are being applied while traveling through mountains with large semi trucks behind me.. nearly causing several accidents. my research points to a few things that could possibly be the culprit: the yaw sensor stearing wheel rotational position sensor vsc computer module this video captures exactly what is happening to my vehicle. https://www.youtube.com/watch?v=tgmjafpifko i cannot find any instances where this issue was fixed online

Vsc light turned on after front wheel alignment, two dealers cannot make it go off. it appears that stabilization was not working for some time. light only appeared after alignment procedure. electronics are part of a $2700 abs module. abs works. no indication of the lack of vsc is a safety issue. others have seen this problem. apparently toyota redesigned the system for the next year's model.

At 108190 miles i had the front end aligned. they attached a snap on analyzer and did a code link computer reset. as i left, the vsc light came on and would not turn off in spite of doing a zero point calibration. i took the vehicle to the toyota dealer where i bought the van new on 5/8/2003, he ran his diagnostics, got no error codes, and claimed that i needed to replace brake actuator assembly at a cost of $2721. out of warranty. no recall on this model. too bad. others have seen this problem on other 2004 toyota's. the danger is that after the light is on the vehicle may decide to apply hard braking at any time and at any speed. toyota redesigned the system in 2005. i am concerned that this will happen to me. toyota recalled some vehicles with this problem with the vsc system in later models, why not the first year of the problem? i have heard that there is a soft recall for this problem.

Unexpected vehicle stability control activation while driving resulting in automatic braking and unexpected steering pull. i have been experiencing this issue over the past 4-5 years. there have been times where this issue has led to almost striking vehicles around me. i have brought the vehicle to a toyota dealership, but they have not been able to fix the issue. on several online bulletin boards, other owners of toyota sienna have complained regarding the same issue. i just read in the news that similar issues are occurring on 2001-2002 toyota sequoia.

My rear door is not working, i have visited two toyota dealership and they told my the rear lift gate and rear hatch latch both of them needs to be replace. we did that relapacemt . the problem has not being solved, we tried to make the door working manually instead of automatically also this way is not helpful. it looks like we reaching to closed way.

I have experienced the issue with 2004 sienna le with 130,500 miles. traction control kicks in at 45-60 miles per hour on straightaway, clean pavement, no rain, no snow, and brakes car and cuts power. almost lost control of vehicle when it happened, steering into other lanes. it happens frequently and is very possible to have the car rear ended if a car behind me is closing on as the speed suddenly slows down. apparently this is a big issue that i found lot of other sienna owners is sharing from the forum. as far as i know that many toyota dealership is not intend to acknowledge such issue and able to fix them.

When driving through a turn (more often at highway speeds) the car traction control activates when there is no emergency. this is always accompanied by beeping, flashing tcs light, and sometimes by emergency braking which slows car and takes it off the intended line creating a dangerous situation for the driver and cars nearby.

Vehicle stability system engaging brakes unexpectly during turns placing van in unsafe condition. unexpected braking can also occur at 65 mph in a turn!

The following has happened several times over the past couple years. the latest 2 times were on a ramp at about 25mph coming off an interstate and at about 65mph an interstate. while cornering to the left a fair amount, but well under control, the vsc started alarming and kicked in. when it kicked in, it caused the vehicle to swerve hard to the right as if it had locked up the brakes on the right side of the vehicle. in both cases, the vehicle swerved into an adjacent lane. had anything been in that lane or had we been in an outside lane, the vcs would have caused a serious accident. whatever the cause, the vsc in this vehicle is very dangerous. over the 12 years we've owned the vehicle, it's unlikely that the vsc has come on more than 5 times. since it's so rare, we drivers have no experience with the behavior and the vehicle is compliant until the vsc kicks in. when it kicks in, the car has presumably determined that some stabilizing action needs to happen, yet, instead of providing safety - the very purpose of vcs, it unexpectedly locks up the brakes on one side of the vehicle and causes it to swerve out of its lane. note, the vehicle has recently had a brake job. under hard braking, the vehicle stays in its line, and does swerve at all, so it's whatever the vsc is doing to "provide stability" that's causing the lockup/swerve issue. finally, from the internet, a couple quick queries led me to postings by other sienna owners who'd experienced very similar behavior, so this is not an isolated incident.

Every time the speed of the car reached 33 mph, the vehicle skid control light would start flashing with a continuous beeping sound. when i continued to drive it and took a turn, the car braked and the steering wheel was not responsive. a very dangerous feeling on the windy roads i live on.

Tl* the contact owns a 2004 toyota sienna. while turning the vehicle at various speeds, the electronic stability control light illuminated and the vehicle became very difficult to control. the contact stated that this was a longstanding issue with the vehicle. the vehicle was not diagnosed or repaired. the failure mileage was 100,000.

Purchased 2004 sienna xle awd limited 2/18/15. while commuting to work the traction control system randomly activates in dry conditions (usually on downhill angled turn) causing loss of power, activation of front right brakes, and the steering wheel jerked from my hands (resulting in transient overall loss of control of vehicle). this defect has occurred 6 times in 2 days and i am currently afraid to drive the car, especially with a 3 month old. there have been multiple reports on edmunds.com and other toyota forums that support this is an ongoing problem with this model/year vehicle. this is a safety defect and the vehicle should be recalled to prevent injury or fatality and to resolve the issue with the tcs. there is no way to turn off the tcs manually and this issue can cause an accident. *tr

Driving along on 210 freeway east bound in pasadena doing 60, the traction control kicked in, the van braked, and the traction control light on dashboard came on with a beeping sound, and the steering wheel shuttered and car lost power. lasted about 5 seconds and then back to normal. could have been rear-ended or could have swerved into other lanes. also happened on 110 fwy northbound in pasadena, 60 mph, on slight turn, same thing happened, traction control kicked in, the van braked, and the traction control light on dashboard came on with a beeping sound, and the steering wheel shuttered and car lost power. i came close to hitting fwy divider and swerving into car in adjacent lane. roads were dry and no slippage of wheels felt. took it to dealer wondries toyota in alhamba,ca twice and were unable to duplicate. *tr

Sudden deceleration of vehicle: 2004 toyota sienna xle. the vsc engages, without warning, on smooth, dry roads and when cornering or negotiating a curve. we are the original owners and have never experienced this until the first incident in late oct. 2014. we did not take any action because although road conditions good, we were rounding a sharp bend in the road and assumed this had something to do with the incident. vehicle speed was approximately 25 mph as the vehicle suddenly decelerated, the vsc light came on and a rapid beeping alarm sounded. the vehicle pulled to one side and steering the vehicle became extremely difficult. the whole incident, start to finish, lasted approximately 5 seconds. the next incident happened in early december 2014. again, all the above described things happened, except vehicle speed was approximately 35 mph going around a gentle curve in the road. i did some research and found many complaints concerning this issue but do not see any recommendations or recalls officially issued by toyota. it appears most of the dealer recommended repairs did not correct the problem. today (december 26, 2014), this same issue happened five times within 40 minutes. my wife managed to get the vehicle home and we called our local toyota dealer, described the issue and they informed us they have never received any complaints concerning rapid deceleration of this model year, before our phone call. i've scheduled an appointment for december 30, 2014 to have the vehicle checked out and have recall work done concerning the "shift lock solenoid assembly". will update after appointment. *tr

While driving on interstate vsc warning light came on, beeping and alarms heard. engine slowed down and i felt like the vehicle was out of control. the vehicle swerved like it was hydroplaning on a dry highway. called our repair shop immediately. car was towed and research was done on the history of the problem in other toyota mini vans. i was told there were reports of this happening in other vehicles but not enough for a recall to be issued by toyota, recommendation by the report they found was to replace a sensor which is what was done. that was just over a month ago and the same problem occurred again tonight on a side road going approx 30 mph on dry road. van is back at shop again tonight. i will be calling the 1-800 number for toyota, i do not understand why there is not a recall on this issue. both incidences could have resulted in an accident. tonight i was driving with my child in the van. this issue could have placed her life in danger had there been an accident. *tr

while driving the vsc activates, the brakes engages, the cars slows down and it make it difficult to control. it has happened to me more than 10 times. mind you its on a dry surface and no curves. very scary i drive it with nobody inside just in case... thanks *tr

It started a year or so ago the while driving on dry road above 50miles the vsc light would lit with a alarm sound, the van will automatically apply brakes and slow the sienna. since this was extra van and we were driving mostly sedans we had and due to business i could not spend any time on it.. now it happens more frequently and it risk our lifes on highway. upon searching internet various forums came with with problems pertaining only to this year and model, please search (sudden vsc activation) and you will find multiple owner only of 2004 complaining for same issue.. in fact there are to two tsb articles to point to this problem ( tsb-br001-04 and tsb-br004-03) . i would kindly request to investigate the sudden vsc activation in middle of highway. i have spent money to replace tires, aligment balancing to find the issue is widespread.

On clear, dry pavement at moderate (50mph -60 mph) highway speeds, the traction control has unexpectedly engaged. this has occurred multiple times on both slight banking turns and on straight sections of roadway. previous to each incident the vehicle was under predictable driver control with no sudden steering changes; yet the traction control activated causing sudden braking, difficulty steering, audible alarm sounds, and dashboard traction control light illumination. the vehicle is difficult to control during the 5- 10 second durations. continued safe driving can only be done by manually disengaging the traction control system. i note that tires were recently replaced and front end wheel alignment was performed. *tr

Starting from a stop and accelerating up to approx 20 mph, abs tracs vsc lights illuminated with beeping alert, and activation of brakes causing a sudden deceleration. the road was dry, level pavement, no ice, no gravel, driving straight and the brakes were not being applied. there were no conditions that would necessitate the traction control. as the brakes were not being applied at the time of the incident, the rear brake lights would not have illuminated. therefore, any driver behind our vehicle would not have been alerted to the sudden deceleration which could have resulted in a collision. fortunately this was not the case. this is the 2nd time that this issue has occurred with this vehicle. the first was in nov. 2007 (46000 miles in the vehicle). toyota service was not able to find a fault, no codes stored and not able to replicate at that time. they said that they would have a corporate contact get in touch with me. i never heard from them. nothing was resolved. there are at least two tsbs related to the vsc issue (tsb br004-03 and br008-04). neither was implemented. *tr

Tl* the contact owns a 2004 toyota sienna. the contact stated that while driving at various speeds, the vehicle stability control warning light and trac warning light illuminated intermittently. as a result, the vehicle decelerated independently. the failure recurred numerous times. the vehicle was taken to a dealer where it was diagnosed that the steering sensor needed to be replaced. the vehicle was repaired however, the failure persisted. the vehicle was taken back to the dealer where it was diagnosed that the cable needed to be replaced. the vehicle was repaired but the failure persisted. the manufacturer was not notified of the failure. the failure mileage was 70,000.

Summary: sensor in stability control failed and falsely reported crisis situation, causing computer to seize control to slow vehicle and change course. long version: while driving straight on city street, suddenly vehicle slowed and pulled to side, stability control light and audio alarm activated, heard grinding noise that sounded like abs. condition persisted if driving over 5-10 mph. crawled to nearby non-dealer repair shop. diagnosis/solution: steering angle sensor reporting wheels at 250 degrees when actually straight ahead, would not recalibrate, circuit integrity otherwise good, sensor was replaced. no residual problems noted so far since then (one day). i have the failed sensor. this sensor problem was cause of a production change and tsb br008-04 in the first year. obviously toyota has known about this problem for years, but no recall. other accounts exist on line of people who have had this happen. this is a major safety hazard. it's the mechanical equivalent of riding with a driver on lsd who is braking/swerving to avoid hallucinations. i was lucky to be going slowly on an uncrowded street, but at higher speed or crowded conditions this could be a disaster. toyota has not been terribly helpful so far, but discussion will continue.... *tr

On numerous occasions, (the first incident occurring november 2013 and most recent 6/23/2014), the stability//traction control system suddenly engaged. most of the incidents occurred while on the freeway with speeds between 50-55 mph, usually on straightaway sections, sometimes during a gentle bank usually toward the right. on all occasions, the roads were dry and the driver was not applying the brakes at the time. without warning, the brakes suddenly engage causing the van to feel like it was lunging forward and making it difficult to control the vehicle. a series of rapid beeps would occur and the traction sensor would illuminate. the entire episode would last for several seconds. during these episodes, the vehicle is difficult to control and passengers/other drivers are in danger. *tr

The vehicle stability system activated while travelling 75 mph on the interstate. the car was travelling on a section of road that curved to the left. due to the braking action induced by the vsc at the highway speed, the car swerved and almost hit vehicles in the other lanes. the car has exhibited this behavior many times, and there are at least two sections of road where i can make it happen at will. due to the extreme danger of losing control of the car while it is applying the brakes, i have disabled the vsc system, causing loss of anti-lock brakes, vsc, etc. this is a common problem with a lot of complaints on multiple web sites.

In the early summer of 2013, i was traveling north on i-15, approx 5 minutes to st. george, utah on a beautiful clear day when the car began to swerve and the yellow skid light came on and the emergency beeping sound alarmed and the car slows down on its own--i no longer have control over accelerating the speed of the car. it frightened and alarmed me and my passengers. within about 5 seconds the light went off and the alarming beeping sound stopped and now i have control of the speed of the car. i have traveled that road several times since and the same incident has occurred at approx the same spot. however, in 2014, during my travels to and fro on this same highway where the speed limit is 65-75mph, the incident occurs in several other spots along i-15 north and southbound. the skid light and the alarming beeping sound even went off when coming to a stop going approx. 5mph. the indicator light and alarm sound seems to be getting more and more sensitive. the same incident has been occurring this year every day on my way home from work at the same spot on i-215. even though the speed limit is 65mph, i have to slow down to less than 50mph in order to avoid this occurrence. this creates a very hazardous situation since i am slowing down for apparently no reason to the cars behind me who are traveling at the speed limit. *tr

My car is a 2004 toyota sienna awd xle limited. the vehicle will activate the vehicle skid control (vsc) without warning while driving on smooth dry roads. the effect is for the vehicle to apply brakes strongly to specific wheels pulling the car strongly to one side. this happens most frequently while driving winding roads and in corners. it has become more regular it it's occurrence and has happened on relatively straight sections of highway most recently. a similar situation occurred approx 2 years ago. at that time the retailer repaired it by adjusting the steering sensor used by the vsc and stated that this should be done periodically dependent on alignment work done on the vehicle. this solved the issue at that time. it is very dangerous both to the vehicle which requires great effort to maintain control and the vehicles following it which are at risk of rear ending the effected car. the toyota retailer initially indicated that a catalyst failure was the cause (yes they said this). i was told that the cat failure could induce other brake and engine related failures. the cat was replaced and the vsc failure has resumed. at this time no failures of any kind are indicated. i have researched this topic and find about a dozen identical failures on 2014 toyota siennas documented in various user forums. as there are only a few documented on the nhtsa site i am concerned that the situation is under reported. many of these user forums indicate that the symptoms were reported to the manufacturer. my most recent trouble report case number from toyota is [xxx]. information redacted pursuant to the freedom of information act (foia), 5 u.s.c. 552(b)(6). *tr

This has been happening regularly for at least two years: traction control seizes control of car when traveling anywhere from 35-65mph, but it happens most frequently on freeway at about 60mph. the car is usually on a gradual curve but it also happens when the vehicle is traveling on a straightaway. vehicle becomes difficult to control, steer, accelerate, lights on the dash light up and a terrible noise ensues. one independent mechanic and two toyota dealers have attempted to troubleshoot the problem and have been unsuccessful. when traction control is manually turned off at engine power-on, the lights still light up showing it is attempting to seize control, and in one instance, control was seized despite the system supposedly being shut down. it is terrifying for the driver as well as any passengers. *tr