Dozens of owners of the current third generation Toyota Prius models have filled complaints with the National Highway Traffic Safety Administration about the alleged brake failures they have experienced.
The Office of Defects Investigation has at least 33 complaints that we are aware of from Prius owners alleging a problem or safety defect, often about the design or performance of the braking system, which recharges the battery when the Prius decelerates.
Some owners describe this as unintended acceleration, but a review of the complaints by TheDetroitBureau.com leads me to think that this is an issue about how the braking system is calibrated. Whether this is a safety related defect is ultimately up to NHTSA to decide. The safety agency is authorized to order manufacturers to recall and repair vehicles when ODI investigations indicate that they contain serious safety defects in their design, construction, or performance.
For Toyota, it is another owner satisfaction or quality issue, at a minimum, coming from its most advanced technology vehicle at a time when Toyota is under attack for its handling of safety matters.
Braking performance issues?
In the case of the Prius brakes, it appears that the transition from regenerative braking to hydraulic braking is not transparent to drivers. Under certain conditions, the driver needs to press harder on the brake pedal to obtain the same stopping performance that the regenerative system working in conjunction with the hydraulic brakes initially provides. Drivers are clearly upset by longer than expected stopping distances when the antilock system shuts off the regenerative brakes.
“What I, and others have been experiencing, is certainly not “runaway acceleration” or anything to do with pressing the gas pedal,” Robert Becker, an unhappy owner of a 2010 Prius, told TDB.