Toyota has come under fire for an unintended acceleration problem in its vehicles, which the National Highway Traffic Safety Administration says may have accounted for over 80 fatalities. The NHTSA slapped the Japanese automaker with a 16.4 million dollar fine for not responding quickly enough to the problem.

Now, NHTSA head David Strickland is saying the cases need further investigation to prevent future accidents, according to BusinessWeek. While Toyota claims that faulty floor mats stuck on pedals caused the problem, there is widespread speculation that the true cause might be in electronic control systems.

"We must do everything possible to fully understand if there are vulnerabilities in these systems to cause this happening," Strickland told the news source. He went on to say that problems similar to Toyota have been reported for “every major automaker,” although not as widespread. NASA is currently looking into the matter on behalf of the agency.

The problems marred Toyota’s previous sterling reputation for safety. Until the cause of the issues are found, safety-conscious drivers may want to look at used cars without electronic control systems.