DETROIT -- The U.S. government's top auto safety official is denying a senator's claim that his agency failed to thoroughly investigate unintended acceleration in Toyotas.
Senator Charles Grassley sent a letter to the National Highway Traffic Safety Administration this month saying that key questions remain about whether electronic glitches caused Toyota vehicles to accelerate on their own.
He questioned whether NHTSA has enough expertise in electronics and why it called in NASA scientists.
But NHTSA chief David Strickland says his agency has ample experience, and NASA was called in to take a second look. Strickland says NASA also couldn't find electronic causes. The government blamed the problems on driver error, sticky gas pedals and floor mats trapping accelerators.
Toyota has recalled more than 14 million vehicles worldwide due to acceleration complaints.
