2021 Toyota Redundant Sienna: brake failure

Filed May 28, 2025 · Brakes · CA

When braking, the brakes will unexpectedly slip. There is generally a loss of brake and a split-second surge that is rather like acceleration (since the car is no longer being slowed down by the brakes). This occurs unexpectedly, unpredictably and without any warning. Having the car suddenly move forwards without brakes is dangerous and could cause the car to hit a pedestrian or another car. This has also happened multiple times while angle parking which almost caused a collision. Two Toyota dealers and a Firestone Tire Center have been unable to replicate the braking issue and tell me that there is no problem with the braking system. I have had both of them inspect the car multiples times, and the issue continues to happen.

Filed Sep 6, 2023 · Brakes · 28,800 miles · MD · crash · 1 injury

The contact owns a 2021 Toyota Sienna. The contact stated that while his wife was parking, she depressed the brake pedal however, the vehicle failed to stop. A message displayed on the instrument panel “Parking brake failure see dealer”. As a result, the vehicle crashed into a wall. The air bags failed to deploy. The contact’s wife sustained injury to her neck and shoulder. Medical attention was required. A police report was not filed. The vehicle was towed to the undisclosed dealer’s service center lot. The vehicle had not yet been diagnosed or repaired. The manufacturer was notified of the failure and the contact was advised to contact the federal safety agency Hotline. The failure mileage was approximately 28,800. The contact stated that their vehicle continues to display the same message about the parking brake. They are unwilling to drive their vehicle.

Filed Jul 21, 2023 · Brakes · NC

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??

Filed Sep 8, 2022 · Brakes · 28,000 miles · SD

When braking under a load - such as braking while descending a hill - the vehicle will be slowing as anticipated when the brakes are applied, and then for a split second the vehicle feels like the brakes disengage. The pedal pressure doesn't change. The vehicle may not actually speed up, but it definitely feels like it's no longer decelerating. Then a split second later the brakes kick in again and the car responds as expected. This happens nearly every day I drive the vehicle and has since it was new. I've got 28000 miles on it now. I've not hit anything as a result, but it makes for a stressful few seconds - even though I now anticipate it will happen. The explanation I've been given is that the sensation of momentary brake failure is the vehicle transitioning between regenerative braking and mechanical braking. However, this definitely doesn't seem like a normal and acceptable way for a vehicle to function.

Filed Jun 13, 2022 · Tires · NC

While traveling in the far left lane of a four lane highway with a speed limit of 70 mph my car started to fish tale but I was able to control it. The cars behind me saw the blowout of my rear passenger tire and slowed down so that I could move to the far right breakdown lane. No warning light came on at any time to alert me of any problems with any of the tires. I always maintain the correct tire pressure. I had a tire company replace all four tires because I was afraid of the other three tires doing the same thing. When I picked up my car the next day the service dept said the brakes didn't work. I had to have the Sienna towed to a Toyota dealer to repair a crushed brake line caused by the blowout. We kept the tire and have taken many pictures.

Filed Jul 26, 2021 · Acceleration, Brakes · CA · crash · 1 injury

We were driving down the freeway when we got rear ended hard by a large pickup. Then we lost electrical and engine power. The brakes stopped working. The hazard lights stopped working. Luckily we were able to coast to a complete stop as there was no way to stop the car. The police came and took a report. Then the car was towed to a body shop. We're awaiting the insurance company adjuster for inspection.