Consultants say interference in vehicle electronics is possible
March 23, 2010
WASHINGTON -- Testing by Toyota Motor Corp. and other automakers has never detected electronic causes of sudden acceleration because it has looked for the wrong evidence and because this evidence is difficult to detect, three British consultants with doctorates in engineering said today.
The consultants, who expect to meet tomorrow with U.S. investigators, said Toyota's pedal assembly and electronic throttle-control system have a number of parts that aren't shielded against electromagnetic interference, or EMI.
“Thirty years' empirical evidence overwhelmingly points to (sudden acceleration) being caused by electronic system faults undetectable by inspection or testing,” said Keith Armstrong, a engineering consultant from the United Kingdom who appeared with two other engineers at a Washington news conference organized here by consumer advocates.
Armstrong, who said he was interviewed last month by U.S. National Highway Traffic Safety Administration investigators, said the problem with electronic interference is industrywide. “EMI is endemic in electronics,” he said. EMI is electrical disturbances in the circuits.
Tests by Toyota and other automakers don't cover most real-life EMI, nor do they simulate typical faults to verify that backup measures work, Armstrong said.
NHTSA is looking into possible links between electronic defects and loss of speed control.
Studies have shown that Toyota has had more complaints about unintended acceleration over the past decade than any other automaker.
The company has recently recalled 8.5 million vehicles worldwide, and consumers have reported 52 deaths from sudden acceleration in Toyota vehicles, NHTSA has said.
“They said all automakers electronics are subject to faults due to EMI, none of the automakers have designed systems that can detect it, much less prevent it, no automakers have properly shielded their electronics or designed fail-safes or black boxes or brake override systems that actually work reliably,” said Toyota spokeswoman Cindy Knight, who was listening in on the press conference.
She continued: “Toyota has sold more than 40 million cars and trucks with our electronic throttle control system (ETCS) and we are very confident that the system is not the cause of unintended acceleration.
“Toyota engineers have comprehensively tested our ETCS under both normal and abnormal conditions including electromagnetic interference, and we have never found a single case of unintended acceleration due to a defect in the system.”
Toyota's top executives recently told congressional committees that their tests over the years had repeatedly shown no evidence of electronic interference with acceleration.
Not addressing the problem?
Engineer Armstrong said Toyota's installation of brake-override systems on many recalled vehicles “does not address the real problem.”
“A true safety override must be a totally independent system,” he said.
Toyota is planning to install brake override systems, which cut the engine when both the brake and the accelerator pedals are depressed, in all 2011 vehicles.
Joan Claybrook, a former NHTSA administrator and president emeritus of Public Citizen, who organized today's news conference, said the three engineers expect to meet with NHTSA tomorrow.
The other two consultants on the panel were Antony Anderson and Brian Kirk.
A NHTSA spokeswoman did not immediately respond to a request for comment.