There is growing concern about the calibration of the brake system in the 3rd-generation Prius. More and more owners are starting to report that they're unhappy with the braking performance of their Prius, some even going so far as to say they fear for pedestrian safety while driving.
The National Highway Traffic Safety Administration (NHTSA) has the final say on whether or not this is a safety issue, but for Toyota, they have another potential customer relations nightmare on their hands. Something they’re very familiar with.
Prius Brake System Design
The Prius uses a braking system that recharges the battery as the car decelerates. Some argue that the transition from regenerative braking to hydraulic braking is what’s throwing drivers for a loop. Under certain conditions the driver has to press harder on the brake pedal after the regenerative braking kicks off and that sudden change can be alarming to drivers, resulting in longer than expected stopping distances. But can you blame them?
The problem with braking on bumpy roads
What’s perhaps even more concerning to drivers is when their vehicles fail to stop when traveling over potholes, recessed manhole covers and other rough road surfaces. According to an internal memo at the National Highway Traffic Safety Administration (NHTSA), it appears when hitting a bump the “regenerative braking (front wheels only) cuts out, and then there is a short delay until friction braking kicks in.”
“The brakes on this car quit working for a second when braking over rough spots. But, of course, not always. The most recent event (of 4) made it obvious why we needed to get rid of this car: I was in a parking lot, approaching the main road, gently braking. When the car hit a pothole at the driveway, the ‘skid’ light came on and the brakes failed long enough for the car to pull into the road. It feels like it accelerated, but not sure about that.” - Brian D of Augusta, GA
The entire city of Boston must feel like an ice rink to Prius drivers.
“We are aware of the complaints filed with NHTSA. The agency has not opened an investigation. We are investigating the issue based on internet traffic, customer comments to Toyota Customer Relations, and NHTSA complaints. It is too early to speculate the final conclusion(s) of our investigation and subsequent actions.”
Better get on that, guys.