2021 Toyota Redundant Sienna

The brake sometimes does fade. Hard to explain but a sudden feeling like the car isn't stopping when slowing down for a light or someone crossing or needing to brake. This is potentially very dangerous since today I almost ran a red light because the brake let go briefly. This is a wide known issue and a lot of people are complaining about it, but dealers aren't able to replicate it because it happens and goes. My 2021 Sienna was brand new, and I first had it and thought it was supposed to be like that. The issue disappeared for months before coming back again 4 times this week alone. The car is very well maintained and only taken to dealer. This is an article from a forum of many people also experiencing it: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Periodically, when I press on the brake to slow down for a red light or stop sign or to make a right hand turn, my van, instead of slowing down, surges forward as if it is accelerating. It feels as if my vehicle jumps forward. I am able to stop the vehicle by slamming on my brakes. I believe my safety and the safety of others is at risk each time this occurs as I worry it will happen when I need to stop suddenly for a pedestrian or for another vehicle. The problem has not been reproduced. The issue occurs sporadically. It may be weeks before it reoccurs. I went for a ride along with a service manager but was unable to reproduce the issue. It has not been inspected except at the dealership. No warning lamps appeared. This issue has been occurring since June 21, 2021. I have kept a log since then.

went to stop, so I pressed on the brake pedal. as I slowed down, the brakes released and the vehicle surged forward suddenly as if the accelerator pedal had been pressed. i panic stomped the brake pedal and the vehicle started braking again with a sudden hard stop. The pedal had to be lifted and depressed again for the brakes to reactivate. during this short time, the vehicle surged forward and accelerated. No, I was not pressing the accelerator pedal. Yes, the vehicle is available for inspection. The vehicle surged forward suddenly while braking. I was not pressing the accelerator pedal. There was no one in front of me, but had there been, I am unsure if the vehicle would have stopped in time, or if the AEB would have even worked, seeing as I was pressing the pedal and the brakes were not working. toyota has said that nothing is wrong, and that I am feeling the "transition" between regen braking and friction braking, except, the vehicle GAINED speed, as if power was being applied to the electric motors instead of regen resistance drag. The brake pedal no longer worked, and the fake "tachometer" went from in the "CHG" section of the tach to the "neutral" position, despite me pressing the brake pedal. I did not have time to see if it went up, as I had to lift up and stomp on the pedal again to get it to actually stop at the stop sign. I have been unable to reproduce this issue on demand, as I cannot quite figure out the conditions that trigger it, as it seems completely at random when it does it. I have some ideas, but toyota has been unwilling to listen or address it. every time a dealer tech sits in the van with me and connects their computer, it won't do it, and they won't leave it connected to the car long enough for me to drive/record a whole day or two to get it triggered. There are no warning lights or messages on the dash.

2021 Toyota Sienna Hybrid. The following has been true from the beginning of ownership of new Sienna. When braking for a turn or stop, as speed drops below about 10-15 MPH, there can be a sudden power/speed surge and lurching forward that lasts for 1-2 seconds. This feels as if there are no brakes at all for those 1-2 seconds Dealer says that that's just the way that hybrids are, that once your speed drops below when the EV system had been regenerating electrical energy. But it is scary because, if for example a child jumped in front of the car at that moment, there may not be adequate braking. The dealer says there is no software fix to smooth the transition from regenerative braking to "normal" braking. WHY ISN'T THERE??

While braking and in a slight turn the vehicle lunges forward. I have learned to compensate for this but prior to compensating I was involved in a rear end crash that was the result of this defect. I was stopped behind this person when she pulled forward. I started pulling forward and she slammed on the brakes. I attempted to stop and the vehicle lunged forward striking her vehicle. The person rear ended claimed no injuries as well as uninjured children properly restrained in the vehicle. She was fully ambulating without complaint. She is now claiming injuries and filed a lawsuit.

The braking system will disengage randomly during braking for a stop. Results in the vehicle lunging forward. There is no warning when it happens and no codes. It has happened at least once a week if not more since gettingthe vehicle. I have brought it up to the toyota service center but they won't look at it without charging a fee.

A sudden feeling like the car isn't stopping when slowing down for a light when applying break. Here is more detailed kind of incident - A sudden feeling like the car isn't stopping when slowing down for a light or when braking down hill, but it happens at other times as well. Sometimes a normal traffic light. I'm braking and then all of the sudden the car feels like it isn't slowing down and kind of jumps and then I just make sure I keep my foot on the break to make sure veh stops I noticed it when I first got the vehicle every so often but when I hit about 40,000 miles got worse , but it seems to be getting worse Currently have 67,000 miles on vehicle, but just had service and it is great most of those miles are road miles it was doing it every so often, but now doing it even more often

The vehicle has had rocks get in the suspension 4 times so far which creates loud clunking noises and can cause a noticeable feel in the steering. The most recent time, after the rock entered the front end, the brakes were soft and required excessive pedal force followed by a clunk before the brakes abruptly applied. I like on a paved road with a rock driveway and it seems like the shielding for the front end is inadequate. I have friends with a 2022 sienna that live on a gravel road that have experienced similar issues.