As Congress holds hearings to find out more facts about unintended acceleration in Toyota vehicles, a preliminary government report found that the company misled the public about the adequacy of auto its efforts to solve the problem.

While Toyota U.S. President James Lentz told the public that the causes of unintended acceleration were floor mats that entrap the accelerator and sticky accelerator pedals, private explanations differed, according to a letter sent by lawmakers to Lentz on Monday, ahead of a hearing today in Congress about the issue.

Toyota had no studies linking sticky pedals to sudden unintended acceleration, Congressmen Harry Waxman and Bart Stupak wrote in preliminary conclusions reached after reviewing thousands of pages of documents submitted by Toyota on February 5.

The letter sent yesterday was signed by Rep. Henry Waxman (D-Calif.) and Bart Stupack (D-Mi, members of the House Committee on Energy and Commerce.

The recalls announced in the last several months provide remedies only for the high-speed sudden unintended acceleration events caused by floor-mat entrapment, and the lower impact, slow-to-idle events created by 'sticky pedals,' the lawmakers wrote, citing a letter from Toyota lawyer Theodore Hester.

Floor mats or pedal problems have been identified as the cause of only 16 percent of the sudden unintended acceleration reports received through a Toyota complaint telephone line, the letter stated.

More than 80 percent of complaints do not identify either of those factors as causes of the reported problems, the letter stated.

In addition almost 70 percent of sudden unintended acceleration events in Toyota's customer call database involved vehicles not subject to recalls in 2009 and 2010 involving floor mat and sticky pedal recalls, the letter stated.