"I want to be absolutely clear," Uchiyamada told members of the Senate Committee on Commerce, Energy and Transportation, "as a result of extensive testing, we do not believe sudden unintended acceleration" was caused by "defect" in electronic throttle control systems, The Los Angeles Times reported Tuesday.
The committee is one of three Washington panels investigating recalls concerning loss of speed control in Toyota vehicles.
In earlier testimony, U.S. Department of Transportation Secretary Ray LaHood said the Obama administration is considering a law mandating brake override systems in every car.
"We think it is a good safety device, and we're trying to figure out if we should be recommending it," LaHood told members of the Senate Committee on Commerce, Energy and Transportation, which is investigating two Toyota Motor Corp. recalls concerning loss of speed control in vehicles.
The systems that deactivate the accelerator when the brakes are pressed are already installed in many cars. Toyota has begun installing the systems in Camry, Lexus and Avalon cars and said last week it would install override systems in Tacomas, Venzas and Sequoias, The New York Times reported Tuesday.
Notable deaths of 2014 [PHOTOS]