By Harry Stoffer
Automotive News / March 22, 2004
WASHINGTON — A relatively new technology, the electronic throttle, is a leading suspect in a wave of claims that some vehicles unexpectedly accelerate out of control.
Government investigators are looking at 2002-03 Toyota Camrys and Solaras and Lexus ES 300s to determine whether they are defective. More than a million of the cars are in service.
The National Highway Traffic Safety Administration has begun a preliminary investigation of the latest claims. It is gathering information about 37 complaints of sudden acceleration by owners of the Toyota and Lexus cars.
The complaints include 30 reports of crashes. They involved injuries to five people; one of them was seriously hurt.
If NHTSA decides that the added data warrant more study, it will upgrade its investigation to an engineering analysis. If the review identifies a defect, NHTSA would push for a recall.
The specter of sudden acceleration has surfaced before. In the 1980s, Audi of America Inc. was nearly driven out of the United States by claims that its Audi 5000 sedan was prone to accelerate suddenly and uncontrollably.
Claims dropped after Audi installed shift-lock mechanisms, which require a motorist to step on the brake before shifting into drive or reverse. All vehicles with automatic transmissions, including those with electronic throttles, now have shift locks.
NHTSA has concluded in many previous cases that most incidents of sudden acceleration are caused not by vehicles’ defects but by drivers’ errors. Drivers mistakenly stomp on gas pedals, instead of the brakes, the agency says.
Nearly every automaker has faced such claims from time to time. Most of the cases allege faults in cruise control systems.
The Second U.S. Circuit Court of Appeals in 2002 reinstated a $1.1 million judgment against Ford Motor Co. in response to the crash of a 1991 Ford Aerostar. Jurors had found that the crash was caused partly by a "negligently designed" cruise control system.
In the largest known judgment on the issue, a Missouri jury last year ordered General Motors to pay an injured woman and her husband $80 million for the crash of a 1993 Oldsmobile Cutlass that they blamed on sudden acceleration induced by cruise control. GM is appealing, a spokeswoman says.
Drive by wire
Toyota Motor Sales U.S.A. Inc. has not claimed that the latest complaints are wrong but says it has not found similar records of complaints or warranty claims in its files.
Toyota spokesman John Hanson confirmed that electronic throttles first appeared in the vehicles under review in the 2002 model year. The technology is spreading gradually throughout the Toyota and Lexus model lines, he says.
The system uses sensors to indicate the position of the accelerator pedal. A control unit obtains signals from the sensors to adjust the throttle valve and thereby change engine speed. Electronics replace the traditional mechanical connection between the pedal and the throttle, such as a cable and linkage.
NHTSA also is investigating electronic throttles in some 2002-03 Ford F-series pickups and Excursion SUVs. Complaints in that case deal with inability to increase engine speed, not unexpected acceleration.
Clarence Ditlow, director of the consumer group Center for Auto Safety, isn’t convinced. He says he believes malfunctioning cruise control systems are to blame for many sudden acceleration incidents.
Other advanced electronics, including throttles, also could be sources of problems, Ditlow says. "We are very concerned about it as you go more and more to drive by wire," he says.
Ditlow is co-author of a new book called Sudden Acceleration: The Myth of Driver Error. The book seeks to refute NHTSA’s findings that most incidents of sudden acceleration are caused by driver error. It also accuses automakers of withholding evidence.
The authors, including a professor of engineering and another professor who specializes in electronic systems, acknowledge that electronics help reduce vehicle emissions and improve safety components. But they argue that the auto industry should not force "its customers to debug its electronics."
They write: "The automotive environment, with its broad temperature and humidity variations and vibration – and the long reliable life expected of motor vehicles – can be a particular challenge for electronics that display failures even in more benign circumstances," as in personal computers and home appliances.
The authors cite the industry’s efforts to increase the use of electronics in vehicles while trimming costs.
They say: "This pressure can reduce the quality of electronics and electronics integration, thus raising the risks of intermittent faults and defective operation."