2021 Toyota Redundant Sienna: sudden unintended acceleration

Filed Sep 24, 2024 · Brakes · MI

Unexpected sudden acceleration when braking at low speed

Filed Sep 11, 2024 · Brakes · MO

Intermittently and randomly the vehicle will lunge forward with the brake applied. I engage the brake, the vehicle slows and then lunges/lurches forward as if I were not braking. Not only is this terrifying but it is also extremely dangerous. This has happened many times since purchase in February 2021 and continues to now.

Filed Jun 6, 2024 · Acceleration, Brakes · TN

Sometimes when each of us 2 are slowing to a stop while applying the brake, the Sienna will lunge forward. This unexpected event may cause a rear-end collision if too close. Also, it is enough to cause us to hit our head on the head rest. Can’t understand why this happening. We are sure we only have our foot on the brake and not the accelerator.

Filed May 2, 2024 · Brakes · CA

When applying the brakes, the brakes sometimes feels as if though it "slips" and the brakes momentarily release causing the vehicle to feel like its suddenly accelerating. This has happened on several occasions -- on downhill and on flat roads. After the brake feels like it slips, then the brake returns back to normal.

Filed Aug 21, 2023 · Brakes · TX

Since the day I bought the van new from a Toyota dealer, the brakes periodically (roughly once a week) will feel as if I've momentarily let off the brake and tapped the accelerator. In other words, the decelerating van suddenly has a quick surge forward or lunge of acceleration. It seems quite random when this happens. I'm usually applying a gentle to medium amount of braking and the van is traveling somewhere in the 5-35 mph range. I've yet to have any close calls, but it is a scary sensation (as if the brakes have momentarily given out) and I have to quickly react by pressing down harder on the brake pedal. Because it occurs quite randomly, I haven't taken the vehicle to the dealer yet as it is highly unlikely I'll be able to replicate the issue for them. I searched online and saw that hundreds of other Sienna 2021-23 drivers are reporting the same issue. To repeat: the problem has not been reproduced or confirmed by a dealer, nor inspected by the manufacturer, police, insurance rep or others. No warning lights come on when this issue happens. I currently have 36,000 miles on the vehicle. The issue has happened almost weekly since I first bought the vehicle.

Filed Jul 25, 2023 · Brakes · MN

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.

Filed Jul 5, 2023 · Brakes · PA · crash

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.

Filed Jul 20, 2022 · Brakes · MN

At 7:35am on 7/20/2022, I was traveling south on Clementa Ave SW in Monticello, MN. The conditions were dry and the sun was out. As I approached the intersection of 127th St NW, I began to slowly press the brake pedal. The vehicle started slowing down, but approximately 5 seconds after pushing the brake, the vehicle automatically let off the brakes, the vehicle lunged forward for about 1-2 seconds, even though I was continuously pushing on the brake pedal. The vehicle’s brake system then re-engaged and the vehicle stopped. This is not the first time this issue has happened and the dealership does not have any resolution to this issue. They attempted a software update, even though my VIN is not included in previous brake issues. This issue happens daily and poses a safety risk if I were attempting to brake behind other vehicles. The release of the brakes and lunging of the vehicle should not happen and feels like the vehicle is out of control.