2024 Toyota Sienna Hybrid

On rare occasions (about once every 500 miles), when uniformly applying force to the brake pedal, the deceleration suddenly ceases and the vehicle seems to jerk forward. To a passenger, it feels like the driver's foot slipped off the brake pedal, but the driver continued to provide the same uniform force to the brake pedal and lost all deceleration. Typically, the driver is startled and presses significantly harder on the brake pedal jerking all occupants forward. The brakes re-engage and continue the deceleration at a much higher rate. Toyota addressed this problem with TSB 4724 which involved reprogramming the brake actuator assembly. This corrected the problem for about 3 months, but it is now occurring again. When the car was taken to the Toyota dealer again, the technician stated that TSB 4724 was cancelled, he could not duplicate the action (even though he was told it only happened on rare occasions), and claimed that the "brakes function properly as they should." Fortunately these loss of braking incidents have only occurred on dry pavement so that the driver did not lose control of the car when slamming on the brakes to compensate for the loss of deceleration. Coming down a hill on a snow covered road could have caused the vehicle to slide into an oncoming lane. It is my speculation that there is a null spot that exists during certain circumstances which causes there to be a "gap" between when this hybrid vehicle transitions between the dynamic hybrid brake and the friction wheel brake. Both braking systems independently work fine, but the transition between them (on rare occasions) does not occur continuously. This causes the driver to experience an unexpected loss of braking which, under the right conditions, could cause the driver to loose control of the forward motion of the car. As an engineer, I feel it is unacceptable for a safety system (braking) to not properly operate 100% of the time! On a Toyota owner's site, others have seen the same.

On June 5 th the vehicle was going approximately 50 miles per hour in the middle lane. I placed on the brakes suddenly and car lost power and stalled out. Unable to restart vehicle for 5-10 minutes on the freeway. Significant safety concern due to vehicles sudden stall out in mid the highway traffic and unable to restart car. Almost hit from behind as well as others that followed from behind. On Jun 7th vehicle was taken to the Toyota dealership and car checked by special mechanic and reported that they were unable to reproduce the stalling or issues with restarting the vehicle.Dealership feels there is nothing wrong with vehicle. There was 2 warning messages on vehicle when stalled suddenly 1-Charge 2- Fluid

When going down hill while braking, the brakes will release causing the car to lurch forward and then they grab again. It’s intermittent and Toyota has a TSB on it but the dealership with not fix it because they can’t duplicate the problem. It can cause people to take their foot off and of the brake pedal and trying to apply it again. Which can cause someone to rear end another car.

The lift gate strut bent when I tried to close the rear door, then when I tried to open the door to see what the issue was, the strut exploded. The parts went flying and almost hit me in the face, I could feel the air on my cheek as it blew past me. The spring and metal parts inside the strut shot all the way across my cul de sac, and the noise it created sounded like a gunshot. My neighbors came out of their houses to see what happened because it was so loud. We have an appointment at the dealer tomorrow to get it looked at. If I was standing any closer the spring would have hit me in the face; my children luckily were in the car already, if it happened a minute earlier it could have hit them. I noticed after the fact that the gaps in the back door are uneven when it’s closed, and I wonder if the door is installed unevenly and that put pressure on one side more than the other causing the strut to break. I can’t take a picture of the broken strut because I am too afraid to open the rear door in case the other one explodes.

In general the braking system on this vehicle is poor. The van does not seem to want to stop unless you apply a lot of pressure on the brake pedal. I have taken the vehicle to the dealership who explained to me that the braking operation is normal. I replied “so the poor brake design was intentional”. The dealer said the braking system takes a little while to get used to. I have contacted Toyota corporate 5 times to express my concern about the brakes. The customer service representatives say that they will pass my concerns along. I personally own 6 vehicles. The brakes on this Toyota are by far the worst. It is not even close. I do not feel like this vehicle is safe. This is a minivan that is used to move families around. I do not feel safe in this vehicle and most importantly I am worried every time my wife drives this vehicle that someone will slam on the brakes in front of her the van will not stop in time. Toyota is the world’s largest auto maker, they can and should produce a better braking system than what is available with this van. This is unacceptable with braking technology available at this time in automotive history. Their lack of response to my concerns in also disappointing. Thank you for hearing my concerns.

There are no messages/warnings. The vehicle will surge at very low speeds such as when I am coming to a stop, trying to avoid a person in a parking lot etc. It was SO scary this evening as I accelerated into a very very busy intersection...I pressed on my brakes harder and it was instant - but about 1 second (which is a LOT in this scenario) later it then slowed instead of accelerated. I have owned the vehicle almost a year. I will be bringing in for inspection this week and let the dealer know. I have put on about 11K in miles and would say this has happened a dozen times thus far with this evening being the scariest one yet. I figured it was just something normal for a hybrid but as I researched online - many people have this issue. TOO SCARY for me and dont want to hurt anyone or myself.

The contact owns a 2024 Toyota Sienna Hybrid. The contact stated that while the vehicle was parked, the transmission was shifted into reverse, and the rear end of the vehicle vibrated abnormally. The vehicle was taken to an independent mechanic but was not diagnosed or repaired. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was not available.