Both the National Highway Traffic Safety Administration and NASA were unable to find any defects in Toyota's source code that could cause problems.
The company has been dogged by fines for not reporting problems in a timely manner.
Earlier this month, NHTSA doled out a record $17.4 million fine to Toyota for failing to quickly report floor mat problems with some of its Lexus models. Toyota paid a total of $48.8 million in fines for three violations in 2010.
Toyota President Akio Toyoda appeared before Congress last year and pledged to strengthen quality control. Recent sales figures show the company appears to have rebounded following its safety issues.
Settlement website: http://www.ToyotaELsettlement.com