Toyota demo counters claim of electronic acceleration glitch
Tuesday, March 9, 2010
Embattled Japanese auto giant Toyota launched a broad counter-attack on Monday aimed at refuting research that suggests electronics may be at the heart of runaway acceleration problems that have led the automaker to recall more than 6 million vehicles.
Toyota's prime target was Southern Illinois University engineering professor David Gilbert, who testified before a congressional panel last month and appeared on an ABC News report showing how he short-circuited the electronic acceleration system in a Toyota Avalon to create runaway acceleration, and suggested such an event could happen under normal driving conditions.
On Monday, Toyota held an elaborate news conference at its North American headquarters in Torrance, Calif., and presented company officials, engineers from an outside firm and a Stanford University engineering professor. It dramatically replicated Gilbert's experiment on several vehicles made by rival automakers that had been parked in the briefing room.
"We did what Dr. Gilbert and ABC should have done to test the real-world relevance of Dr. Gilbert's findings," said Toyota spokesman Mike Michels. Gilbert's experiment was "completely unrealistic. He rewired and reengineered a vehicle in multiple ways in a specific sequence that is impossible to occur."
The criticism was echoed by J. Christian Gerdes, associate professor of mechanical engineering at Stanford and the director of the school's Center for Automotive Research, which is funded with money from Toyota and several other automakers.
Toyotas, like all modern vehicles, use an electronic linkage between the gas pedal and the engine, not a mechanical one, as older vehicles did. In his experiment, Gilbert had tapped some of the six wires that send signals to the engine when a driver steps on the gas pedal and bridged the wires to create a short circuit. Then, he applied a small voltage that caused the engine on his test vehicle to race, causing sudden acceleration.
Gilbert noted that the Toyota's engine computer did not diagnose the short circuit as a problem or issue an error message. Because the situation did not produce an error message, the vehicle's fail-safe system -- which is designed to cut engine power in such a situation -- did not engage.
Though careful not to personally attack Gilbert, Toyota and its consultants argued that engineers can rewire and re-engineer anything to make it fail. "We could rewire this building and cause it to go into flames," said Subodh Medhekar, principal engineer with Exponent, the outside company Toyota hired to diagnose the runaway acceleration problem.
Toyota also used Gilbert's technique to short-circuit several non-Toyotas and achieved the same result -- a racing engine. In the large room where Monday's briefing was held, Toyota displayed a Ford Fusion, Chevrolet Malibu, Chrysler Town & Country and Crossfire, Subaru Outback, BMW 325 and other vehicles. During the briefing, officials from Toyota turned on the vehicles and reproduced Gilbert's experiment. In each vehicle, the engine raced and no error message was seen on diagnostic tools.
In an e-mailed response to Monday's presentation, Gilbert wrote: "Over the next several days, I will examine their expanded results and conclusions along with my own. I will visit Exponent next week to get a first-hand look at the information presented today and discuss their methods and procedures. I hope to complete my review of all the information within the next few weeks."
Edmunds.com senior editor Bill Visnic said Toyota's display was thorough.
"Toyota really chipped away at the evidence provided by Dr. Gilbert during the congressional hearings," Visnic said. "Toyota demonstrated today that Gilbert's hardware test does not provide a uniform probable cause for all unintended acceleration claims."
Toyota was asked about the more than 80 reported cases of runaway acceleration in vehicles that have already been recalled and supposedly fixed. A company official said that Toyota was aware of those reports and had been able to verify only a few of them. Among those that Toyota had been able to track down, the company believes the recurring runaway acceleration was caused by improperly performed recall repairs.
When asked if the company thought it had a software problem, Toyota said it was confident that is not the case. Nevertheless, Exponent and the National Highway Traffic Safety Administration are looking into Toyota software. The software issue has been called by some "the ghost in the machine."
Toyota's Kristen Tabar, general manager of electronics systems, said: "There isn't a ghost issue out there."