The problem of sticking accelerators in Toyota automobiles was the result of mechanical problems, not faulty electronics, the U.S. Secretary of Transportation said Tuesday.
A stuck gas pedal in a loaner Lexus sedan in Santee nearly two years ago caused a crash that killed an off-duty California Highway Patrol officer and three members of his family. Lexus is Toyota's upscale brand.
Toyota has denied that its electronic throttle control system was to blame for instances of sudden acceleration, and said in a statement that is welcomed the findings of the 10-month investigation, which was requested by Congress.
"We believe this rigorous scientific analysis by some of America's foremost engineers should further reinforce confidence in the safety of Toyota and Lexus vehicles,'' said Steve St. Angelo, Toyota's chief quality officer for North America.
"The statement by Transportation Secretary Ray LaHood came at a news conference to announce findings of an investigation by the National Highway Transportation Safety Administration and NASA engineers.
"Our conclusion is this — Toyota's problems were mechanical and not electrical," LaHood said.
It was revealed after the August 2009 wreck at the northern terminus of state Route 125 at Mission Gorge Road that gas pedals were sticking in certain vehicles manufactured by Toyota, some after coming into contact with floor mats.
Those are the only causes identified in sudden acceleration incidents, according to the report.
There were accusations that electrical problems played a role, but LaHood said engineers found no problems with electronics.
The car maker recalled 8 million vehicles to fix accelerators.
Shortly before the crash, Officer Mark Saylor, 45, dropped off his regular car at Bob Baker Lexus in El Cajon to be serviced, and drove away in the loaner vehicle.
As the car barreled down the hill at the end of the 125, someone in the car called 911 to report that they were gaining speed and could not be stopped.
The automobile struck an SUV at more than 100 mph at Mission Gorge Road and crashed through a fence before exploding on the bank of the San Diego River. Saylor's 45-year-old wife, Cleofe, and 13-year-old daughter, Mahala, and 38-year-old brother-in-law, Chris Lastrella, also died in the crash.
The Saylors resided in Chula Vista, and Lastrella was visiting from The Philippines.
Toyota Motor Corp. agreed to pay relatives of the Saylors $10 million in a settlement announced last December. A lawsuit by the family against the Lexus dealership is pending.
Toyota faces about 200 lawsuits over reported sudden-acceleration incidents.