The president of Toyota's U.S. operations acknowledged to skeptical lawmakers on Tuesday that the company's recalls of millions of its cars may "not totally" solve the problem of sudden and dangerous acceleration.
"We are vigilant and we continue to look for potential causes," Toyota's James Lentz told a congressional panel. However, he repeated his company's position that unexpected acceleration in some of the company's most popular cars and trucks was caused by one of two problems - misplaced floor mats and sticking accelerator pedals.
He insisted electronic systems connected to the gas pedal and fuel line did not contribute to the problem, drawing sharp criticism from lawmakers who said such a possibility should be further explored - and from a tearful woman driver who could not stop her runaway Lexus.
Rhonda Smith, of Sevierville, Tenn., said at a congressional hearing. Then she added a second "shame on you" directed at federal highway safety regulators.
Texas Republican Rep. Joe Barton cautioned his colleagues early in the hearing against conducting a "witch hunt" and said "We don't want to just assume automatically that Toyota has done something wrong and has tried to cover it up." But midway through Lentz's testimony, Barton said of Toyota's investigation of the problems: "In my opinion, it's a sham."
Much of Lentz's testimony dealt with sudden unintended acceleration - the malfunction Toyota has insisted is caused by sticking gas pedals or bunched floor mats. Toyota's malfunctioning brakes and steering were almost afterthoughts, reports CBS News correspondent Dean Reynolds..
Lentz was asked if he believes Toyota's repairs will fix the acceleration issue. But his answer, "not totally," was less than heartening.
"We have to fix the process so it doesn't happen again. Who knows what's behind the curtain," Lentz said.
Question after question dealt with what many suspect could be the real cause - the cars' electronic systems.
But through it all, Lentz insisted the electronics are not to blame, Reynolds reports - even in the face of testimony from one witness who said Toyota's electronic throttle is different than other cars' and that in three and a half hours of testing he'd shown their fail safe systems can indeed fail.
Lentz said the company had not completely ruled out an electronics malfunction and was still investigating causes of the sudden acceleration. Still, "We have not found a malfunction" in the electronics of any of the cars at issue, he said.
As to Smith's harrowing story, "I'm embarrassed for what happened," Lentz said. "I want her and her husband to feel safe about driving our products," Lentz said.
Lentz briefly appeared to tear up during his testimony, saying that he lost a brother in a car accident shortly after the brother's 30th birthday. "That was twenty-some years ago," Lentz said. "And there's not a day that goes by that I don't think of that. So I know what these families go through."
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Three congressional panels are investigating Toyota's problems, which affect a huge number of Americans. Toyota has recalled some 8.5 million vehicles worldwide - more than 6 million in the United States - since last fall because of unintended acceleration problems in multiple models and braking issues in the Prius hybrid. It is also investigating steering concerns in Corollas. People with Toyotas have complained of their vehicles speeding out of control despite efforts to slow down, sometimes resulting in deadly crashes. The government has received complaints of 34 deaths linked to sudden acceleration of Toyota vehicles since 2000.
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Lentz has said in the past that he was confident Toyota's fixes on the recalled vehicles would correct the problems.
But when pressed by Energy and Commerce Committee Chairman Henry Waxman, D-Calif., on whether the two recalls Toyota put in place to deal with the issue would completely solve it, Lentz replied: "Not totally."
Still, he said chances of unintended accelerations were "very, very slim" once the recall was complete. Lentz also said Toyota was putting in new brakes that can override the gas pedal on almost all of its new vehicles and a majority of its vehicles already on the road.
Meanwhile, Toyota president Akio Toyoda, who will testify before a separate panel on Wednesday, said he took "full responsibility" for the uncertainty felt by Toyota owners and offered his condolences to a California family who were killed in late August, reigniting interest in the problems.
"I will do everything in my power to ensure that such a tragedy never happens again," Toyoda said in prepared testimony for Wednesday's hearing to the House Government Oversight Committee. "My name is on every car. You have my personal commitment that Toyota will work vigorously and unceasingly to restore the trust of our customers."
Lawmakers heard a brief, but riveting, description from Smith, the Tennessee woman whose Toyota-made Lexus suddenly zoomed to 100 miles per hour as she tried to get it to stop - shifting to neutral, trying to throw the car into reverse and hitting the emergency brake. Finally, her car slowed enough that she was able to pull it off the road onto the median and turn off the engine.
Fighting back tears, she described her nightmare ride of October 2006, calling it "a near death experience."
"After six miles, God intervened" and slowed the car, she said. She added that it took a long time for Toyota to respond to her complaints.
In an often contentious full day of testimony, lawmakers returned again and again to the question of whether electronic malfunctions may have contributed to the speeding cars.
"We are confident that no problems exist with the electric throttle control system in our vehicles," Lentz said. He cited "fail-safe mechanisms" in the cars that were designed to shut off or reduce engine power "in the event of a system failure."
Despite Lentz's claims of confidence in the electronics systems in Toyota vehicles, CBS News has learned that as early as 2005 Toyota engineers were of cars surging unexpectedly, reports CBS News Correspondent Sharyl Attkisson.
Transportation Secretary Ray LaHood told the panel in prepared testimony that possible electronics problems were being looked into by his agency. He said the company's recalls were important steps but "we don't maintain that they answer every question."
Toyota hired a consulting firm to analyze whether electronic problems could cause unintended acceleration. The firm, Exponent Inc., found no link between the two. But committee investigators said the testing studied only a small number of vehicles
Tracking down an electrical problem can be far more difficult, expensive and time-consuming than finding a mechanical problem. Electrical problems can have more than one source, and they can come from inside or outside the car. Mechanical problems often leave clues such as physical damage, where electronic troubles can be hidden in software or leave no trace at all.
House investigators who reviewed Toyota's customer call database found that 70 percent of the complaints of sudden acceleration were for vehicles that are not subject to the recalls over floor mats or sticky pedals.
And the car site Edmunds.com says that between 2005 and 2010, the number of complaints about Toyota automobiles unintentionally accelerating to the National Highway Traffic Safety Administration was greater than five of its biggest competitors combined, Reynolds reports.
Rep. Bart Stupak, D-Mich., chairman of the subcommittee, said Toyota "misled the American public by saying that they and other independent sources had thoroughly analyzed the electronics systems and eliminated electronics as a possible cause of sudden unintended acceleration when, in fact, the only such review was a flawed study conducted by a company retained by Toyota's lawyers."
Lentz apologized anew for the company's slow handling of problems. "We have not lived up to the high standards our customers and the public have come to expect from Toyota," he said.
"Put simply, it has taken us too long to come to grips with a rare but serious set of safety issues, despite all of our good faith efforts," said Lentz, president and chief operating officer of Toyota Motor Sales USA. Inc.
Separately, among hundreds of Toyota dealers lobbying members of Congress Tuesday, there seemed to be widespread rancor toward a federal government they view as , at least in part because of the government's investment of billions of dollars in General Motors and Chrysler.
"That's hard for me as a citizen to understand why my tax dollars are going in that direction," Paul Atkinson, a Houston-area Toyota dealer, said at a news conference that also served as a pep rally for the visiting dealers. "To compete with the government as an individual entrepreneur is pretty tough."