Toyota Refutes Researcher's Simulation of Unintended Acceleration
March 08, 2010

Toyota Motor Corp. battled back yesterday against a hurricane of negative publicity and Congressional calls for action related to unintended acceleration in its Toyota- and Lexus-brand vehicles.

The controversy takes a new twist as Toyota and Exponent Inc., the high-profile engineering consultancy and troubleshooter the company has hired, demonstrated the unintended acceleration-causing conditions produced in a highly publicized test for Safety Research and Strategies Inc. conducted by Dr. David Gilbert, an associate professor of automotive technology at Southern Illinois University at Carbondale, are highly unlikely to occur under real-world conditions.

The Exponent team also showed that the design of Toyota's wiring for its electronically controlled throttle - the component suspected to be at the root of unintended acceleration - is engineered to prevent the potential for the kind of failure Gilbert's testing generated.

Toyota also asked a mostly unrelated third party, Dr. J. Christian Gerdes, associate professor of mechanical engineering at Stanford University and the director of the Center for Automotive Research at Stanford (CARS), to examine the evidence both Gilbert and Exponent presented.

Gilbert's testing and the testimony of Gilbert and Safety Research and Strategies founder Sean Kane repeatedly was invoked by members of the U.S. House of Representatives in hearings last month as strong evidence Toyota's engineers had been thorough in investigating potential hardware-related causes for unintended acceleration - and that its electronically controlled throttle design could be compromised, making it the possible explanation for years' worth of reports of unintended acceleration in various Toyota vehicles.

Throughout those hearings, Toyota staunchly defended the robustness of its electronically governed engine throttle system.

In detailing what they called the misrepresentative impression Gilbert's testing generated, Exponent and Toyota also slapped around ABC news for its segment on Dr. Gilbert's results. The news organization originally presented a patently misleading representation of a moving vehicle's engine behavior once the simulated unintended acceleration was induced, but Toyota's objections caused ABC to re-edit the footage available online to accurately depict how the engine behaved in the moving vehicle.

More than once, Gilbert and Safety and Research Strategies were referred to as "paid advocates for trial lawyers" currently suing Toyota.

The exponent engineers stressed that Gilbert's process to simulate unintended acceleration by reengineering the electronic throttle control's circuitry was "completely unrealistic" and that it provides "no evidence of a real-world circuit malfunction that throttle system's built-in fault-detection software wouldn't detect and signal."

And after the convincing media demonstration in which Exponent engineers used Gilbert's methodology to replicate runaway engine operation (that would be tantamount to unintended acceleration) on a variety of vehicles made by several different automakers, including Ford, Mercedes-Benz and BMW, a Toyota spokesman reiterated, "We're confident in our electronic throttle systems," and added, "We do not believe electronics are at the root of this issue."

Hardware Cleared, But What About Software?

In the course of today's demonstration, Exponent engineers showed how a series of improbable conditions would have to occur to deliver the wide-open throttle Gilbert's test was able to simulate.

They also stressed that if such conditions did affect the wiring of the electronic throttle pedal assembly, there would be visible evidence - and no such evidence has been found on any components.

The research conducted by Exponent convincingly refuted the testimony from Safety Research and Strategies' Dr. David Gilbert that was used in testimony before the U.S. House of Representatives in late February. In that testimony, Gilbert said he had caused the simulated unintended acceleration after just a few hours of research and that his method did not trigger a fault code in the engine-management system that is designed to default the engine to a failsafe operation mode.

But while Toyota and Exponent's demonstration seems apt rebuttal to the initially damaging Safety Research and Strategies testing that Congressmen and many critics have pointed to as evidence Toyota's electronically controlled throttle's hardware could be compromised, Toyota and the Exponent engineers admit it does nothing to eliminate the possibility that some as-yet unknown software fault could send an aberrant signal to the engine's electronically controlled throttle.

Exponent's engineers said they continue to work around the clock to determine if there may be an undiscovered software-related fault in Toyota's engine-control computer, but it so far has found no problems.

A Toyota spokesman also downplayed the potential for faulty software as the explanation for why some 60 drivers of Toyota vehicles that have undergone the fixes Toyota spelled out under conditions of two massive recalls have reported their vehicles continue to display unintended-acceleration behavior.

The spokesman said "we are aware of the reports" of repaired vehicles still evidencing unintended acceleration, but only a few reports have been verified - and that in some of those vehicles, "it had to do with the repair not being done properly."

All the engineers on hand for Toyota's staged demonstration to dispel the possibility for hardware malfunctions as the cause for unintended acceleration admitted the latest testing cannot dispel the possibility for a software-related related explanation, although one Toyota engineer said a software problem also is improbable.  - Bill Visnic, senior editor

Photos by Toyota

Dr. Matthew Schwall of Exponent, Inc. demonstrates how engineers replicated a 1. reengineered circuit used by another engineer to simulate unintended acceleration in a Toyota vehicle.

2. Dr. Chris Gerdes, director of Stanford University's Center for Automotive research, examined the research of all engineers testing Toyota's electronically controlled throttle system.
 

 

Posted by Bill Visnic at 8:58 PM under Featured , In the Media , News , Technology , Toyota | Comments (3) | digg this | Seed Newsvine

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