Toyota Motor Co. has not ruled out an electronic malfunction as a cause of unintended acceleration in its vehicles which has led to a major global recall.

Toyota U.S. sales chief James Lentz said in a congressional hearing today that the company has commissioned an independent study by an outside consultancy, Exponent, on the issue of its electronic throttle and that it had not discovered any electronics issues so far.

He said, however that the initial Exponent report was preliminary and that a full report at a later date would be released publicly.

Lentz was asked by Rep. Henry Waxman (D-Calif.) today if he believed that recalls of vehicles over floor mats and sticky pedals addressed all cases of unintended acceleration in the vehicles.

Not totally, Lentz said in testimony today before a Congressional panel investigating the issue.

We need to be vigilant and search for all the consumer complaints, he said.

A study of documents submitted by Toyota to Congress that was recently and examined by the House Energy and Commerce Committee found that 70 percent of calls made to a Toyota complaints hot line over sudden acceleration were not related to faulty floor mats or sticky pedals.

Toyota has recalled millions of vehicles over the issue in recent months.

Improving Complaints System

Lentz said the company is improving the way it handles customer complaints.

We have new processes in place that will ensure transparency to make changes, he said.

Lentz said that determinations about defects or recalls had been previously made in Japan but said that would change.

He said the company would be creating a safety board that would include representatives from around the world.

If a representative disagreed with the company's decisions on recalls, they would be able to appeal the decision, something that hadn't been available so far, Lentz noted.

The President and Chief Executive of Toyota Motor Corp. in Japan, Akio Toyoda. Will testify tomorrow before lawmakers.

In prepared statements released today to be read during testimony in Congress, he said he was deeply sorry for any accidents that Toyota drivers had experienced.