Embedded Expert: No Pedal Misapplication in Toyota Case

Charles Murray

November 8, 2013

3 Min Read
Embedded Expert: No Pedal Misapplication in Toyota Case

The Toyota unintended acceleration case decided by a jury two weeks ago may have hinged on the testimony of an embedded systems expert who definitively said there was no pedal misapplication. Michael Barr, CTO and co-founder of Barr Group, told the court that the fatal accident involving a 2005 Toyota Camry was the result of a systematic software malfunction, combined with a loss of throttle control.

"The dispute in this case is related to computer software and hardware," J. Cole Portis, attorney for the plaintiffs, said in a summation argument obtained by Design News. "That is what we have talked about; that is the issue in the case..."

The highly publicized case involved a 76-year-old driver who exited an Oklahoma freeway, sped down an off-ramp, and crashed her car. The driver was seriously injured, and her passenger died. The crash occurred in 2007, years before the Toyota "unintended acceleration" incidents became national news.

Toyota argued that the incident was caused by pedal misapplication -- in other words, the driver pushed on the accelerator when she should have stepped on the brake. The 2005 Camry did not have a black box onboard to record the driver's actions prior to the accident.

Barr, who worked on behalf of the plaintiffs, told the court that he hunted through hundreds of thousands of lines of Toyota's software code, spending approximately 15 months and 2,000 hours in the process. He wrote an 800-page report. He was one of a dozen engineers designated by the court to examine the car's embedded computer system. His testimony did not rely on any previous unintended acceleration theories involving loose floor mats, sticky accelerator pedals, or so-called "tin whiskers." Instead, it drilled down into the software code, making the case that Toyota's software "failsafes" had holes in them, which led to a system malfunction. "The failsafes that they have contain defects or gaps," Barr said in sworn testimony. He added that the Camry's safety architecture was "a house of cards."

The failsafes were significant to the case because such systems are put in place by engineers to intercede if the engine's throttle-by-wire control is lost. Barr argued, however, that the failsafes were constructed in a way that might cause them to be unsuccessful in such a situation. "It is possible for a large percentage of the failsafes to be disabled at the same time that throttle control is lost," he testified.

Barr's position seemed to fly in the face of earlier statements made by former Secretary of Transportation, Ray LaHood, in February 2011. "We enlisted the best and the brightest engineers to study Toyota's electronics systems, and the verdict is in," LaHood was widely quoted as saying back then. "There is no electronic-based cause for unintended high-speed acceleration in Toyotas. Period."

Barr argued, however, that NASA scientists who studied the Toyotas had left the door open for other, unexamined possibilities, saying they couldn't rule out the existence of a systematic software malfunction.

About the Author(s)

Charles Murray

Charles Murray is a former Design News editor and author of the book, Long Hard Road: The Lithium-Ion Battery and the Electric Car, published by Purdue University Press. He previously served as a DN editor from 1987 to 2000, then returned to the magazine as a senior editor in 2005. A former editor with Semiconductor International and later with EE Times, he has followed the auto industry’s adoption of electric vehicle technology since 1988 and has written extensively about embedded processing and medical electronics. He was a winner of the Jesse H. Neal Award for his story, “The Making of a Medical Miracle,” about implantable defibrillators. He is also the author of the book, The Supermen: The Story of Seymour Cray and the Technical Wizards Behind the Supercomputer, published by John Wiley & Sons in 1997. Murray’s electronics coverage has frequently appeared in the Chicago Tribune and in Popular Science. He holds a BS in engineering from the University of Illinois at Chicago.

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