WASHINGTON—After recalling over 8 million vehicles worldwide, Toyota Motor Corp. has been on a PR campaign to repair its reputation as well as repair mechanical issues related to sudden acceleration in its vehicles.
But a panel of electrical engineers say that the issue lies in electronics, not mechanical parts, and that Toyota is taking the wrong approach in its investigations, according to a March 23 news conference in Washington.
“Electronics have weaknesses and can go wrong in many ways,” said Euring Keith Armstrong, an electronics expert. “Many electronic throttles are not safe enough, but it is easier to blame drivers, floormats, and sticky pedals.”
Anthony Anderson, an electrical failure expert, and Brian Kirk, a safety software expert agree. All three engineers are from the U.K. Their observations about the behavior of electronics in automobiles is no different than the way electronics behaves in all other industries and is backed up by scientific standards and peer-reviewed papers.
Questions about sudden, unintended acceleration in Toyota and Lexus vehicles are raised every time an incident hits the news. On March 8 James Sikes’s Prius accelerated to 90 miles per hour and could not be stopped on a San Diego freeway by application of the brakes. Unable to replicate the problem, Toyota said that Sikes’s account has little merit.
In another well-publicized case, Mark Saylor, an off-duty California Highway Patrol trooper, died with three members of his family on Aug. 28, 2009, when his 2009 Lexus sped out of control and crashed in Santee, Calif.
On March 25, the Los Angeles Times reported 102 deaths because of sudden acceleration of Toyota vehicles.
Not Electronics Says Toyota
Toyota claims that the issue is due to either unsecured driver’s floor mat, sticky accelerator pedal, or driver error. More than 8.5 million cars were recalled worldwide (5.3 million in the United States), according to Reuters, to remedy the issue—by changing the design of the pedal as well as the floor below it.
Toyota has steadfastly ruled out the electronic system faults as the cause of sudden acceleration. “Six times in the past six years NHTSA [National Highway Traffic Safety Administration] has undertaken an exhaustive review of allegations of unintended acceleration on Toyota and Lexus vehicles and six times the agency closed the investigation without finding any electronic engine control system malfunction to be the cause of unintended acceleration,” Toyota said.
“[Toyota claims] that because they can find no defect after a sudden acceleration incident that the sudden acceleration could not have been caused by a design fault,” said Armstrong. But he says the argument that “an absence of a detectable fault proves absence of a design effect” uses false logic. Most electronic faults don’t leave any evidence, “Especially after the ignition is turned off.” Electronics have weaknesses and can go wrong in many ways, explained Armstrong.
“In most instances it recovers, leaving no trace.”
It’s akin to having a computer go awry. If one reboots the computer, the problem often disappears without a trace, and it may be impossible to reproduce the fault.
The industry went through a revolutionary change when computers began controlling a car’s functions. The throttle used to be directly controlled by mechanics—a metal rod linked the driver’s gas pedal. This design was replaced by the gas pedal and throttle motor being mediated by the engine control module (ECM), which connects to the gas pedal sensors via electrical wires. The system became more vulnerable to electromagnetic interference (EMI). Problems became more evident beginning in the year 2002 when the electronic throttle control was introduced in the 2002 Camry and Lexus ES300.
Some EMI, such as a lightning strike, leaves visible damage, but most types do not have sufficient energy to cause actual damage. “They are weak and do no more than distort or otherwise confuse the electric signals in a circuit, causing it to suffer errors or malfunctions in the operation of its hardware, software or firmware,” Armstrong wrote in a report on his Web site.
The engineer argued that EMC design engineers know its weaknesses, but that automakers—Toyota is only the latest to use this argument of not finding detectable design fault—take advantage of people’s ignorance. It's an excuse not to have to reprogram or change the electronics, he said.