A team of NASA engineers was unable to identify an electronic flaw in Toyota vehicles that could cause potentially deadly sudden acceleration, according to a study released today by the Department of Transportation.
"We enlisted the best and brightest engineers to study Toyota's electronics systems, and the verdict is in. There is no electronic-based cause for unintended high-speed acceleration in Toyotas. Period," U.S. Transportation Secretary Ray LaHood announced today.
The only known causes of the "unsafe and unintended" acceleration in Toyotas were mechanical safety flaws involving the "sticking" accelerators and accelerators becoming trapped underneath the vehicles' floor mat, the study said.
However, the NASA report said that "because proof that the [electronic system] caused the reported [unintended accelerations] was not found, does not mean it could not occur."
"It's not over because tomorrow you could find what the cause is," Clarence Ditlow, executive director for the Center for Auto Safety told ABC News. "There's no doubt in my mind there are electronic problems, but we're talking about a very rare event."
The NASA engineers did find two theoretical scenarios in which the electronic systems could cause sudden acceleration, but found no evidence it had happened in the real world.
In addition to the findings, the NHTSA announced the agency is considering taking several steps to improving driver safety including requiring a brake override system, making "event data recorders" mandatory in all passenger vehicles and researching the placement of the pedals to "reduce pedal misapplication."
"While today marks the end of our study with NASA, our work to protect millions of American drivers continues," NHTSA Administrator David Strickland said in the DOT statement. "The record number of voluntary recalls initiated by automakers last year is also very good news, and shows that we can work cooperatively with industry to protect consumers."
The problem with the runaway Toyotas first came to light after a California highway patrolman couldn't stop the Lexus he was driving in 2007. In a desperate 911 call, a passenger in the car said, "Pray for us."
All four people in the car died in the collision that followed.
In the past two years, Toyota has recalled nearly eight million of its vehicles due to the pedal malfunctions, and paid nearly $50 million in civil penalties after an NHTSA investigation into the problem.
Toyota only admitted the sticky pedal problem in the U.S. after ABC News reported on the case of a New Jersey driver whose car would not stop
CLICK HERE for ABC News' full coverage of the Toyota recalls.
Toyota said in a statement the company welcomed the findings announced today.
"We hope this important study will help put to rest unsupported speculation about Toyota's ETCS-i [Toyota Electronic Throttle Control System-Intelligent], which is well-designed and well-tested to ensure that a real world, un-commanded acceleration of the vehicle cannot occur," the statement said.
Today's finding comes as auto-manufacturing giant also reported today a 39 percent dip in quarterly profits. Though thriving in some international markets, Toyota sales have slowed in the U.S. in recent years, reportedly affected by the widespread recalls.
Despite the DOT's announcement clearing Toyota of electronic sudden acceleration problems, the car manufacturer is still in the crosshairs of a lawsuit filed by dozens of drivers who claim that cases of sudden unintended acceleration have caused them personal injury or financial harm due to the reduced resale values of their vehicles. Multiple lawsuits have been combined into one multi-district federal class action suit h in the U.S. District Court in Southern California.
According to court filings submitted as part of the case, Toyota company documents reveal that its own drivers were behind the wheel in two separate cases when the vehicles experienced sudden acceleration, as their owners had alleged had happened to them. One of the documents states, according to the filing, that a Toyota vehicle unexpectedly accelerated from 71 mph to 95 mph with "no pedal contact" while being evaluated by a Toyota service manager.
Toyota bought both vehicles back from their owners -- who had brought them in complaining about sudden acceleration -- and both owners say Toyota urged them not to discuss the incidents.
The document states, according to the filing, that after proceeding from a stoplight, the "tech[nician] started to lightly accelerate" and after travelling "20-30 feet the vehicle exhibited a slight hesitation and then began to accelerate on its own." Engine speed "was estimated to have gone from 1500 rpm to 5500 rpm at the time of the occurrence," according to the filing.
In another case in Milpitas, California, the owner of a 2009 Toyota Tacoma brought his truck into the Piercey Toyota dealership after complaining that the vehicle accelerated without explanation. According to the court filing, another Toyota internal document states that in July of 2009 a dealership service manager took the vehicle on an inspection drive on a nearby freeway.
"As there was no traffic in front of them, the Service Manager removed his foot from the accelerator [and]moved it completely away from the pedal area," the document states, according to the filing, and "[t]he vehicle continued to accelerate at what felt like [an estimated] 70% throttle input with no pedal contact from the driver [and] within 300 feet of the initial acceleration, the vehicle had reached 95 MPH."
The document states, according to the filing, that the floor mats were securely in place at the time of the incident and no fault codes were generated by the onboard computer and "[a]s the Service Manager who experienced the condition above is considered to be trustworthy and reliable, the vehicle will be repurchased for further investigation."
When reached by ABC News, the owner of the Tacoma confirmed that Toyota had bought the Tacoma back from him and said the dealer informed him that they were able to replicate sudden acceleration in the vehicle. The driver, who asked not to be named, told ABC News that while Toyota did not ask him to sign a confidentiality agreement they urged him not to talk about the case. According to California's vehicle Lemon Law, owners cannot be required to sign confidentiality agreements over vehicles with possible defects.
When asked about the cases by ABC News, Toyota said that it is not unusual for the company to repurchase vehicles "as part of our commitment to investigate acceleration concerns." According to Toyota spokesperson Brian Lyons, owners are not required to sign confidentiality agreements when a vehicle is bought back, but "they enter into them voluntarily as part of a mutual settlement agreement."
In October, the NTHSA told ABC News it would look into the California and Texas cases, but at today's press conference, NHTSA deputy administrator Ron Medford said the agency had "no ongoing investigations" related to alleged incidents of Toyota technicians replicated sudden acceleration in vehicles.
ABC News' Lee Ferran contributed to this report.