Mar 8, 2010 2:39 PM by Bea Karnes, News First 5
Toyota Motor Corp. plans to rebut claims that the electronics of its cars and trucks are to blame for unwanted acceleration problems that are behind the recall of more than 8 million vehicles.
The automaker is holding a demonstration Monday to counter tests by an engineering professor that show Toyota engines can be revved by tinkering with the electronics that control acceleration. Many safety experts have suggested electronics are to blame for vehicles that speed of unexpectedly.
Toyota believes that sticky gas pedals and floor mats are to the cause, and the automaker is in the process of fixing millions of vehicles to correct those conditions. But some drivers have reported continued problems in vehicles that have already been fixed.
Toyota will aim to duplicate the scenario created by David W. Gilbert, an automotive technology professor at Southern Illinois University Carbondale. Gilbert told Congress last month he was able to recreate unwanted acceleration in a Toyota vehicle by manipulating its electronics.
Rep. Steve Buyer, R-Ind., raised questions about Gilbert's testimony because it was partly funded by attorneys who are involved in litigation against Toyota.
Toyota is calling in the director of Stanford University's Center for Automotive Research to try to refute the claims. Toyota said Stanford professor Chris Gerdes will show that the malfunctions Gilbert produced "are completely unrealistic under real-world conditions and can easily be reproduced on a wide range of vehicles made by other manufacturers."
Stanford's Center for Automotive Research is funded by a group of auto companies, including Toyota.
Toyota also has hired a consulting firm to study whether electronic problems could cause unintended acceleration. The firm, Exponent Inc., released an interim report that has found no link between the two.
Gilbert told a congressional hearing on Feb. 23 that he was able to recreate sudden acceleration in a Toyota Tundra, which is covered by two recalls, by short-circuiting the electronic accelerator pedal without triggering any trouble codes in the truck's computer.
Gilbert, during the hearing, said he made a "startling discovery" that showed the electronic throttle control system could have a problem without producing a trouble code. Without a code, the vehicle's computer will not enter in a fail-safe mode that would lead to the brake overriding the accelerator.
House lawmakers seized on Gilbert's testimony as evidence that Toyota engineers missed a potential problem with the electronics that could have caused some vehicles to suddenly surge forward without any warning.
According to an Exponent report last week, Gilbert connected sensor wires from the pedal of a 2010 Toyota Avalon to an engineered circuit. This allowed him to rev the engine without using the pedal. Gilbert demonstrated the method in an ABC News story last month.
Exponent said it reproduced the test on the same model year Avalon and a 2007 Camry and was able to rev the engine. But it concluded that the electronic throttle system would have to be tampered with significantly to create the right conditions.
"Dr. Gilbert's scenario amounts to connecting the accelerator pedal sensors to an engineered circuit that would be highly unlikely to occur naturally, and that can only be contrived in a laboratory," the report states.
Exponent was also able to rev the engine of some Toyota competitors using the same technique. The report stresses the tests do not imply there is any defect with those other brands.
The event planned Monday is part of a broad campaign by the world's biggest automaker to discredit critics, repair its damaged reputation and begin restoring trust in its vehicles.
On Friday, a congressional committee questioned Toyota's efforts to find the causes of the problems. It also questioned whether the company had sufficiently investigated the issue of electronic defects.
Toyota executives also will address recall issues at its annual suppliers meeting in Kentucky on Tuesday.