The Obama administration may recommend that carmakers install a brake override system that is intended to prevent the sudden acceleration episodes that have led to recalls of millions of Toyotas, the transportation secretary, Ray LaHood, said on Tuesday.

Mr. LaHood made his comments at a hearing held by the Senate Committee on Commerce, Energy and Transportation, one of three such hearings in Congress in the last two weeks that examined the Toyota recalls and the response to them by the National Highway Traffic Safety Administration.

Both Toyota and the safety agency faced sharp criticism.

The committee’s chairman, Senator Jay Rockefeller, Democrat of West Virginia, scolded the automaker for failing to listen to American executives’ warnings about rising safety problems.

Last week, officials in Toyota’s North American operations said they did not have the authority to order large-scale recalls, saying the responsibility rested solely with Japan.

At the hearing on Tuesday, the committee released a presentation from 2006 by James E. Press, who was then in charge of Toyota’s sales operations in the United States. In it, he urged Japanese officials to be more transparent about safety matters.

Mr. Press subsequently became the first non-Japanese member of the Toyota board, but left to join Chrysler.

“Safety took a second seat to profits,” Senator Rockefeller said. “Things do not happen in Japanese corporations by chance. They happen by decision.”

Mr. Rockefeller is a longtime ally of Toyota who studied in Japan during college and spent years wooing the company, eventually landing an engine plant from Toyota in Buffalo, W.Va. Nonetheless, he said he was frustrated by a lack of direct answers from senior Toyota executives at the hearing. “There is more knowledge at the table than has disclosed itself,” he said.

Mr. Rockefeller raised the subject of the brake override system. “We’re looking at it,” Mr. LaHood said. “We think it is a good safety device, and we’re trying to figure out if we should be recommending it.”

The override system is meant to deactivate the accelerator when the brake pedal is pressed.

Often called a “smart pedal,” the feature is now installed in many automobiles sold worldwide, including models from BMW, Chrysler, Mercedes-Benz, Nissan and Volkswagen.

Once the system is installed, it will stop the car if both the brake pedal and accelerator pedal are depressed.

Toyota did not install the system on its cars for several years but has now begun putting it on Camry, Lexus and Avalon models. About 20 percent of its vehicles in North America have the override. Last week, the automaker said the system also would be installed on its Tacoma, Venza and Sequoia models.

In a lengthy exchange with Mr. LaHood, Mr. Rockefeller suggested that federal safety officials accepted Toyota’s explanation that floor mats caused sudden unintended acceleration because they did not understand the cars’ computer system, which many drivers and critics have pointed to as a possible cause.

“I think N.H.T.S.A. investigators would rather focus on floor mats than microchips because they understand floor mats,” Mr. Rockefeller said. “It’s a major letdown on N.H.T.S.A.’s part, looking back and up to the present.”

Mr. LaHood said he did not know whether the agency had “turned a blind eye” to the electronics issue, but vowed a “complete review” of the situation.

Toyota executives again tried to assure lawmakers that they were taking steps to rectify the problems behind the recalls. “This loss of trust is more costly than anything else to Toyota,” said Yoshimi Inaba, the head of Toyota’s North American operations.

Executives asserted, as they have before, that the sudden unintended acceleration in Toyota cars was caused by gas pedals that can become obstructed by floor mats or stick because of design flaws, and not by problems in the electronic systems.

“I want to be absolutely clear: As a result of our extensive testing, we do not believe sudden unintended acceleration because of a defect in our E.T.C.S. has ever happened,” Takeshi Uchiyamada, an executive vice president at Toyota, said, referring to the car’s engine throttle control systems. However, Mr. Uchiyamada, the chief engineer on the Prius, said Toyota “will continue to search for any event in which such a failure could occur.”

Through February, the N.H.T.S.A. had received 43 complaints of fatal accidents that are said to have involved unintended acceleration in Toyota vehicles since 2000, the Transportation Department said. The department has not confirmed the complaints, which cover 52 deaths and 38 injuries. Three-quarters of the episodes were reported to the safety agency in the last four months, since Toyota’s initial recall in October 2009.

Toyota executives promised to be more responsive to driver complaints as well as safety warnings from the government, and then assured lawmakers that the company was taking steps to improve quality control.

“It is clear to us that we did not listen as carefully as we should — or respond as quickly as we must — to our customers’ concerns,” Mr. Inaba said.

But the Senate committee released a company presentation in which Mr. Press urged the Japanese parent to give Toyota America “better information” on quality issues.

The document, a slide show presentation and accompanying notes dated 2006, also urged Toyota to “strengthen communications” among the company’s divisions in the United States and Toyota’s headquarters.

“We need faster information flow, and more technical support when hot issues arise,” the notes read. “Transparency is the key to regaining trust.”