NASA engineer Michael Kirsch, left, speaks at a news conference in Washington… (Kevin Lamarque, Reuters )
Reporting from Los Angeles and Washington — Sudden acceleration in Toyota Motor Corp. vehicles is caused by mechanical rather than electronic systems, a federal study found, but regulators said they are considering requiring automakers to install a trio of safety systems designed to reduce the risk on future vehicles.
Transportation Department Secretary Ray LaHood asserted that a 10-month probe conducted primarily by NASA engineers found no evidence that electronic defects or software code errors could account for the thousands of reported cases of sudden acceleration in Toyota and Lexus vehicles over the last decade.
The study concluded the only defects that could cause sudden acceleration involved floor mats that could jam the gas pedal and accelerator pedals that could become stuck. Toyota has already recalled 8 million vehicles in the U.S. to fix those problems.
Even so, consumer complaints of sudden acceleration affect vehicles from all manufacturers and as a result, the National Highway Traffic Safety Administration has begun taking steps to write new standards that could improve safety, LaHood said at a news conference Tuesday.
The auto safety regulator will begin consideration of a rule to require so-called brake override systems, which cut off engine power when a motorist puts a foot on the brake pedal. It is designed to stop a car, even if the gas pedal is jammed.
The agency also will consider standardizing push-button start systems, which can confuse motorists trying to shut off a runaway engine. In other cases, vehicle owners have accidently let engines with push-button starts continue to run after parking.
Finally, the agency wants to require all new cars to be sold with event data recorders, or black boxes, which could help determine the cause of many crashes.
Separately, the agency also is beginning research to determine whether certain pedal designs and placements can reduce the tendency of drivers to hit the wrong pedal.
NHTSA senior officials said the NASA study closely examined 58 cases of sudden acceleration in Toyota and Lexus vehicles and found about two-thirds appeared to involve a driver accidently hitting the wrong pedal.
The results of the study, which was assisted by a team of engineers from NASA Langley Research Center, is good news for Toyota, which has contended for more than year that there is no defect in the design or performance of engine systems that have for the last decade relied on a high degree of electronic control.
"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 $1.5-million study, launched last March, examined nine vehicles that Toyota repurchased from owners after sudden acceleration reports. They were inspected and later subjected to electromagnetic radiation at a special Chrysler testing chamber. The NASA team reviewed 280,000 lines of software code, looking for glitches that could trigger the engine to unexpectedly go to full power.
"The jury is back, the verdict is in: There is no electronic-based cause for unintended high-speed acceleration in Toyotas, period," LaHood declared.
Nonetheless, the sudden acceleration problems have blemished Toyota's once-sterling reputation for quality. Along with floor mats and gas pedals, the Japanese automaker has been plagued by defects in steering components, structural parts, brakes and engine control circuit boards, leading to recalls of millions of other vehicles.
The company has also been slapped by regulators for not disclosing problems when it became aware of them. In December, Toyota agreed to pay $32.4 million in fines for failing to promptly notify regulators and issue a recall when it knew of defects involving the potential for floor mats to entrap pedals and for another defect that could cause a total loss of steering.
And last April, the company agreed to a record $16.4-million fine for delaying notification to regulators about the sticky pedal problem. The fines were the largest ever levied against an automaker.
Complaints about sudden acceleration from Toyota and Lexus owners surged after the automaker adopted the so-called drive-by-wire system starting in 2001. For some Toyota models, reports of unintended acceleration increased more than fivefold after drive-by-wire systems were adopted, according to a Times review of thousands of consumer complaints filed with regulators. Transportation Department officials attributed the surge to publicity, even though it wasn't until 2009 that sudden acceleration became a buzzword.