2004 Toyota Sienna service brakes problems

“The Traction Control System commonly malfunctions while making turns on curving road sections. I will lose power through turns as the TCS light blinks on my dashboard and makes a beeping sound. On some occasions the brakes will automatically engage in the tire that the car perceives as experiencing slippage. This problem is continuously worsening and commonly endangers me and my passengers, as the car engages brakes or cuts power to the engine at unexpected and in opportune times.”

“Vehicle often applies brakes on its own . At first it was only in turns . However now it does it when driving straight on the the freeway or just down the street at 45mph. I have fixed my alignment ,new tires, all of the front suspension and nothing prevents the car from trying to brake for me. it is a safety feature that is not safe at all. a car slamming on your brakes at any speed is dangerous in addition to that it seems to cut off your fuel , leaving you unable to accelerate until its done beeping which can take a long time. the vsc , chenk engine and trac off flash there is no crash to report I have been lucky so far”

“- Traction control engaged at high speed(70 mph on interstate) causing the vehicle to brake abruptly and pull the vehicle to the right. Had I been traveling in the left hand lane, I could have been forced into the right hand lane causing a collusion with another vehicle. Also occurred at lower speed(30 mph on a windy road) causing the same issue as described above, almost causing the vehicle to leave the paved surface. - Mechanic was able to duplicate the issue - Mechanic diagnosed intermittent traction control activation, scanned computer for codes. Yaw rate/steering angle correlation causing false activation ABS/traction. Replaced hub bearing and spindle. Four wheel alignment, including check castor, camber and adjust toe. Performed zero point calibration and reset ABS memory. - Traction control lights up briefly”

“About a year ago the Vehicle Stability Control warning light along with an audible alarm started coming on intermittently while turning on highways going uphill or downhill in dry weather and with no risk of any tire slipping. At first this only happened at higher speeds 65+mph. Over time, it has occurred more and more frequently and can occur at speeds down to 25 mph. At times, the Anti-lock Braking System is also activated resulting in jerky braking and loss of throttle. When people have been following me too closely, this has almost caused accidents. When these symptoms occur, it is always on a curve (of any degree, even slight curves) and while driving at least 25 mph, and even happens on flat turns now. The weather has always been dry with no risk of tire slippage.”

“The failing component is the VSC/ABS system. It puts the occupants of the van and other motorists at risk of either causing a collision or causing the driver of vehicle in question to be unable to control the vehicle . The failure appears when going in a curve in the road at low speed causing the abs to engage lock the brakes and steering wheel rapidly decelerating the car and causing the car to jerk to one side or the other and go into a skid where the driver is unable to control the wheel due to steering wheel locking up when it happens the VSC and TRAC lights come on and there is a loud and rapid beeping that can be heard inside the vehicle. The issue usually appear when going between 25-40mph in banking curves”

“Sometimes when I take turns in my Sienna, the VSC starts going off and braking individual wheels without my control. This happens unexpectedly on highway bends at speeds of 60+ mph and it is difficult to control the car and keep from swerving into another lane. If the roads were icy when this happens, it would probably cause a dangerous accident. Toyota has a technical service bulletin for this, but not a recall - which it should since this is a significant safety issue. The TSB is BR008-04. There are many others experiencing this same issue: https://forums.edmunds.com/discussion/13855/toyota/sienna/vsc-sudden-activation-2004-toyota-sienna”