In a letter to James Lentz, president of Toyota Motor Sales, U.S.A., U.S. Reps. Bart Stupak, D-Mich., and Henry Waxman, D-Calif., said Toyota didn't seem to have a basis for claiming it was confident there were no defects in the electronic throttle controls or other systems, The Christian Science Monitor reported.
Roughly 8.5 million Toyotas were recalled in North America, Europe, China and Japan in recent months for unintended acceleration and braking issues. Toyota officials testified before several congressional committees investigating the vehicles' safety issues.
"It may be that Toyota has done 'extensive' and 'very rigorous' testing of its vehicles for electronic defects," said Stupak, chairman of the House Energy and Commerce subcommittee for investigations, and Waxman, chairman of the full Energy and Commerce Committee.
But if the testing occurred, the two lawmakers said, the results weren't provided to the House committee, the Detroit Free Press reported.
"Despite our repeated requests," the letter said, "the record before the committee is most notable for what is missing: the absence of documents showing that Toyota has systematically investigated the possibility of electronic defects that could cause sudden unintended acceleration."
Stupak and Waxman asked Toyota to make executives involved in the testing available for interviews next week, the Free Press said.