Toyota blames software for Prius braking woes

TOKYO (CNN) -- Without issuing a recall of its iconic Prius hybrid vehicles, Toyota on Thursday said a software glitch is to blame for braking problems in the 2010 model.

"We would want to be given a little time," Hiro Yuki Yokoyama, Toyota's managing officer, said when reporters asked whether a recall was in the works.

The company changed braking system software in January as part of what it called "constant quality improvements," but did not say what it would do about vehicles manufactured before then.

Toyota (TM) officials described the problem as a "disconnect" in the vehicle's complex anti-lock brake system (ABS) that causes less than a one-second lag. At 60 mph, though, a vehicle will have traveled nearly another 90 feet before the brakes begin to take hold.

Brakes in hybrids such as the Prius operate differently from brakes in most cars. In addition to standard brakes, which use friction from pads pressed against drums or rotors, the electric motors in hybrids help slow them. The process also generates electricity to recharge the batteries.

The Japanese government has warned Toyota to take seriously mounting complaints with the Prius. Toyota Vice President Shinichi Sasaki met with Japan's transport minister Wednesday.

In Japan, 14 complaints about brakes in the Prius have been lodged since July. Japan's Ministry of Land, Infrastructure, Transport and Tourism has asked Toyota to investigate, according to the Japan Automobile Dealers Association.

"The complaints received via our dealers center around when drivers are on a bumpy road or frozen surface," said Paul Nolasco, a Toyota Motor Corp. spokesman in Japan. "The driver steps on the brake and they do not get as full of a braking feel as expected."

In the United States, more than 100 complaints alleging poor brake performance have been lodged with the National Highway Traffic Safety Administration against the 2010 Prius, a newly designed version of the car, which was introduced last summer.

"NHTSA has received a number of complaints about a potential defect affecting the brake system in Toyota's Prius hybrid and is conducting field work to examine the issue," the agency said Wednesday.

A search of NHTSA's complaint database turned up many similar-sounding complaints in the United States.

"I have been driving my 2010 Prius for 6 months and have experienced the following nearly 10 times," one owner wrote. "When braking, if a pothole or bump in the road is hit, the car seemingly jerks forward/accelerates for a split second."

The Prius is Toyota's third best-selling model in the United States, ranking behind the Camry mid-size sedan and the Corolla compact car.

Toyota's public image, and its sales, have been hit by recent recalls involving unintended acceleration.

The automaker recalled 2.3 million vehicles on Jan. 21 because of problems with sticking gas pedals and later halted the sale of the eight models involved in the recall.

Toyota's U.S. sales plunged 16% in January as a result, even as the sales of other automakers rose.

Toyota announced third-quarter results Thursday, posting an operating profit of $2.1 billion. The quarter ended Dec. 31, three weeks before Toyota stopped selling the recalled models.

In a separate recall, about 4.2 million vehicles were called back in November because their gas pedals might get stuck in some floor mats. The last-generation version of the Prius was included in that recall, which was expanded to include an additional 1.1 million cars last week.

-- CNN's Kyung Lah and CNN Money's Peter Valdes-Dapena contributed to this report.