In an unprecedented live webcast on Monday, Toyota’s US unit raised serious concerns about the validity, methodology and credibility of a demonstration of alleged “unintended acceleration” in a Toyota Avalon by Professor David Gilbert of Southern Illinois University and depicted in recent ABC News broadcasts and on-line segments. In a statement, the automaker said comprehensive analysis by “a world renowned engineering group”, Exponent, as well as Toyota’s own testing, concluded that, for Gilbert’s demonstration, the vehicle’s electronics were rewired and reengineered in multiple ways, in a specific sequence, and under conditions that are virtually impossible to occur in real-world conditions without visible evidence; Toyota vehicle electronic systems were actively manipulated to mimic a valid full-throttle condition and that substantially similar results were successfully created in vehicles made by other manufacturers. In the demonstration dramatised by ABC on 22 February, Gilbert, assisted by segment reporter Brian Ross, asserted that he had detected a “dangerous” flaw in the Toyota electronic control system that he alleged could lead to unintended acceleration. The following day, Gilbert offered a preliminary report of his findings in testimony to the US House of Representatives Energy and Commerce Subcommittee on Oversight and Investigations. Engineers at Exponent, one of the country’s leading engineering and scientific consulting firms, as well as Toyota engineers, reviewed and recreated Gilbert’s demonstration with substantially similar results in representative vehicles of other makes. Separately, at Toyota’s request, Dr Christian Gerdes, associate professor of mechanical engineering at Stanford University and the director of the Center for Automotive Research at Stanford (CARS), conducted an independent review of Gilbert’s testimony and the preliminary report presented to Congress. Their findings were demonstrated on Monday at a news conference during which the accelerator circuitry of an Avalon, as well as a sampling of competitive vehicle models, was rewired and manipulated as Gilbert did in his demonstration. Kristen Tabar, general manager of electronics systems, Toyota Technical Center, summarized three of the major concerns with the artificial nature of Gilbert’s demonstration. “First, an electrical circuit that has been reengineered and rewired will not behave as it was originally designed and engineered,” said Tabar. “Second, no automaker can or should be expected to design detection strategies for artificially created events in the absence of any evidence that such an event can occur in the real world. “Third, if the artificial condition created by Gilbert had occurred in the real world, it would have left readily detectable fingerprints.” Exponent and Toyota engineers found no evidence to suggest that any of the steps of Gilbert’s demonstration exists in the real world. Thus, the fact that the Avalon used by Gilbert did not show a Diagnostic Trouble Code after his demonstration did not indicate an undetectable safety defect. The same was true of the other vehicles from other manufacturers tested by Exponent and Toyota. Toyota said Gilbert’s reengineering and rewiring of the vehicle’s electrical system involves manipulations in a specific sequence. First, the protective insulation on two separate wires that carry the accelerator pedal position signals to the engine control module must be individually cut or breached. Next, these wires are connected to each other through a 200 ohm resistor. This contrivance, by itself, did not cause an increase in engine speed, Toyota said. To cause an increase in engine speed, it is necessary to cut the insulation on a third wire, the five-volt power supply to the accelerator pedal, and force a low resistance connection between the power supply and the secondary signal wire. The resulting increase in engine speed is a result of the subsequent artificial and sudden application of the five-volt power supply to this signal line with the rewired circuit. When subjected to similar unrealistic reengineering and rewiring, the competitive vehicles evaluated by Exponent and Toyota achieved substantially similar results with varying levels of resistances. This manipulation of electrical components and a power source created artificial voltages that the engine control module, or ECM, would interpret as valid accelerator pedal signals. In essence, this test created a virtual, remote control accelerator pedal that replicated the vehicle’s own normally functioning accelerator pedal. Also contrary to statements made in the ABC News story, had short circuits of the kind artificially created by Gilbert occurred in real-world driving conditions, they would have left visible evidence such as damage or deterioration of the wiring and components. As revealed in their testimony before Congress, Gilbert’s preliminary report was commissioned by Sean Kane, a paid advocate for trial lawyers involved in litigation against Toyota and other automakers, Toyota said, ading that Kane also appeared on the ABC News broadcast in support of the claim that Gilbert’s demonstration revealed a flaw in the electronic throttle control system that could lead to “runaway” Toyota and Lexus vehicles.
“The relationship between Kane, Gilbert and the trial lawyers who support Kane’s advocacy was not revealed by ABC News during the newscast, nor was Toyota offered an opportunity to view the demonstration or given time to respond,” the automaker’s US unit said. “Toyota believes that the public and Congressional committees have been misled by Professor Gilbert’s demonstration and the dramatisation of it by ABC News. This has cast unwarranted doubt on the safety of Toyota and Lexus vehicles. Toyota remains confident in the integrity of the electronic throttle control system in its vehicles and there has been no reliable evidence of any kind to the contrary presented to the media or to Congress. Toyota’s electronic systems have multiple fail-safe mechanisms to shut off or reduce engine power in the event of a system failure. Extensive testing of this system by Toyota has not found any sign of a malfunction that could lead to unintended acceleration.” Toyota said Exponent would continue to conduct a comprehensive analysis of the electronic throttle control systems in Toyota and Lexus vehicles.
“An interim report of Exponent’s findings has been provided to Congress and establishes the functionality of the electronic throttle control fail-safe systems. The final results of Exponent’s exhaustive analysis will be made public when completed. As with all such reliable engineering analyses, Exponent’s final results will provide the data and information necessary for others to validate Exponent’s conclusions.”
Bill Visnic, senior editor at Edmunds Autoobserver.com, told the Detroit News that Toyota’s fight-back had scored it points. “They refuted fairly damning evidence presented before Congress,” he said.
But he raised a point other US commentators made following the Toyota demonstration: “What it doesn’t answer, and what it will not silence, are the doubters who think this could be a software-related issue.”
Gilbert reportedly did not address the criticisms of his experiment on Monday but said in a statement that he had watched Toyota’s presentation and would visit Exponent next week to look at the information presented on Monday.