Toyota Motor Sales (USA) announced yesterday that it would voluntarily recall approximately 2.3 million vehicles to correct sticking accelerator pedals on its 2009-10 RAV4, 2009-10 Corolla, 2009-10 Matrix, 2005-10 Avalon, 2007-10 Camry, 2010 Highlander, 2007-10 Tundra and 2008-10 Sequoia models.
If you recall, Toyota in November 2009 announced that it was recalling 3.8 million of its vehicles to fix their gas pedals that might cause floor mat entrapment. The fixes included both a reshaping of a vehicle's accelerator pedal and a software change to create a brake override capability to allow a vehicle's engine power to be cut off in case of a simultaneous application of both the accelerator and brake pedals.
At the time,Toyota said the solution represented a "root cause" fix and that it was "very, very confident that we have addressed this issue," namely, the cause of sudden unintended acceleration (SUA) problems that led, for instance, to the death of California Highway Patrol Officer Mark Saylor and his family in August.
However, Toyota now admits that its runaway car problem was not only larger in scope than it first thought, but its root cause analysis of the problem was incomplete.
Toyota now admits that floor mats weren't the cause of all runaway incidents involving its cars. It discovered "that there is a possibility that certain accelerator pedal mechanisms may, in rare instances, mechanically stick in a partially depressed position or return slowly to the idle position."
I don't know whether this latest admission will silence the critics who believe that there is an inherent software problem with Toyota's engine control system that causes SUA - I tend to doubt it. This current pedal problem apparently keeps a car at its last "present speed" but doesn't cause it to suddenly accelerate.
About 10 days ago, Toyota announced that it would install brake override systems on all Toyota, Lexus and Scion vehicles by the end of the year to eliminate SUA and I assume any other unknown/undiscovered causes of runaway cars.
Robert N. Charette is a Contributing Editor to IEEE Spectrum and an acknowledged international authority on information technology and systems risk management. A self-described “risk ecologist,” he is interested in the intersections of business, political, technological, and societal risks. Charette is an award-winning author of multiple books and numerous articles on the subjects of risk management, project and program management, innovation, and entrepreneurship. A Life Senior Member of the IEEE, Charette was a recipient of the IEEE Computer Society’s Golden Core Award in 2008.