U.S. Senator Charles Grassley (R-Iowa) is voicing concerns that a government investigation of sudden unintended acceleration in Toyota vehicles may have wrongly ruled out electronic glitches as the cause triggering some vehicles to unexpectedly speed out of control.
A team of investigators from the National Highway Traffic Safety Administration (NHTSA) and NASA engineers studied sudden acceleration in some of the affected Toyota models, but ruled out a malfunction in Toyota’s electronic throttle control system as a possible cause. The conclusion drew the ire of many independent engineers, safety advocates, and other critics who insist the study was flawed.
Senator Grassley says that whistleblowers involved with the study have provided his office with documents indicating the NASA report “may have been too narrow” in its focus. In a letter to NHTSA Administrator David Strickland, Sen. Grassley asked if NASA engineers considered the presence of “tin whiskers,” ultra-thin crystalline which can develop on tin and tin-coated surfaces, creating electrical shorts and leakage paths that cause electronic malfunction.
“This is a very serious issue,” Grassley wrote, noting that just because the NASA scientists didn’t find proof that electronics caused the sudden acceleration phenomenon in Toyota vehicles “does not mean it could not occur.” Indeed, engineers independent of Toyota and the government have warned that pinpointing an electronic cause or trying to replicate it in a lab could be exceedingly difficult.
Last year, an independent study conducted by researchers at the University of Maryland’s Center for Advanced Life Cycle Engineering (CALCE) demonstrated that, contrary to NASA’s conclusions, an electronic cause for the sudden unintended acceleration problem in Toyota vehicles wasn’t just probable, but highly likely. They pointed to the presence of tin whiskers, which have been found on Toyota circuitry, as the likely culprit behind sudden acceleration events.
Toyota, meanwhile, continues to blame sudden acceleration on floor mat interference and driver error. In 2009 the company launched a series of recalls to correct the problem. The measures led to more than 8 million vehicles being returned to dealerships for repairs in one of the largest automotive recalls in U.S. history. Toyota’s initial mishandling of the recall also led to record federal fines.