The National Highway Traffic Safety Administration has recently received a few dozen complaints about the 2010 Toyota Prius’s braking performance. The Prius owners are complaining about a feeling that the car lurches forward when hitting a pothole or other uneven surfaces.
Some drivers believe the problem results when the system makes a transition from regenerative braking, which helps to recharge the hybrid battery, to conventional braking when more aggressive stopping is required. The system is calibrated to use one kind of braking or the other for optimum braking performance and maximum efficiency. The calibration and sensors are apparently not responding well to potholes and bumpy roads, and thereby producing an unpleasant driving sensation, and a safety hazard for pedestrians.
Robert Becker, an unhappy owner of a 2010 Prius, told The Detroit Bureau website, that he experienced a “loss of braking power or braking momentum when hitting a pothole, manhole cover, or the like. This requires the driver to press down again harder on the brakes to slow or stop the car,” said Becker. Other drivers described it as a feeling of losing control for a very brief period—less than a second.
Reports about the braking issue come during a time when Toyota’s longstanding reputation for high quality is coming under question. The company recently recalled nearly 4 million vehicles, reportedly because some floor mats used in Toyota Priuses and other vehicles were forcing down the accelerator pedal, causing rapid uncontrolled acceleration. These incidents could undermine the reputation of Toyota vehicles and hybrids as very safe vehicles. In August, the Insurance Institute for Highway Safety gave “Top Safety Pick” awards to the Toyota Prius and Honda Insight, based on front, side, and rear crash testing.
NHTSA has not yet opened an official investigation into the 2010 Toyota Prius braking issue. Toyota is aware of the complaints, but says that it’s too early to speculate about the cause or, if required, a possible remedy.