Business

Toyota hits the brakes

Company is vehemently denying that drive-by-wire electronic accelerators have anything to do with the up to 20-fold increase of unintended acceleration accidents since the new components were introduced in 2002, saying floor mats are to blame

  • By Ken Bensinger and Ralph Vartabedian, Los Angeles Times-Washington Post News Service
  • Published: 00:00 December 1, 2009
  • Gulf News

  • Image Credit: Supplied picture
  • 2002 is the year drive-by-wire accelerators were first installed at Toyota.

Eric Weiss was stopped at a busy Long Beach, California, intersection last month when he said his 2008 Toyota Tacoma pickup unexpectedly started accelerating, forcing him to stand on the brakes to keep the bucking truck from ploughing into oncoming cars.

Toyota Motor Corporation says the gas pedal design in Weiss' truck and more than four million other Toyota and Lexus vehicles makes them vulnerable to being trapped open by floor mats, and recently announced a costly recall to fix the problem.

But Weiss is convinced his incident wasn't caused by a floor mat. He said he removed the mats in his truck months earlier on the advice of his Toyota dealer after his truck suddenly accelerated and rear-ended a BMW.

"The brakes squealed and the engine roared," the 52-year-old cabinet maker said of the most recent episode. "I don't want to drive the truck any more, but I don't want anyone else to, either."

Amid widening concern over unintended acceleration events, including an August 28 crash near San Diego that killed a California Highway Patrol officer and his family, Toyota has repeatedly pointed to "floor mat entrapment" as the problem.

But accounts from motorists such as Weiss, interviews with auto safety experts and a Los Angeles Times review of thousands of federal traffic safety incident reports point to another potential cause: the electronic throttles that have replaced mechanical systems in recent years. The Times found that complaints of sudden acceleration in many Toyota and Lexus vehicles shot up almost immediately after the automaker adopted the so-called drive-by-wire system over the past decade. That system uses sensors, microprocessors and electric motors to connect the driver's foot to the engine, rather than a traditional link such as a steel cable.

For some Toyota models, reports of unintended acceleration increased more than five-fold after drive-by-wire systems were adopted.

Complaints

Toyota first installed electronic throttles in 2002 model year Lexus ES and Toyota Camry sedans. Total complaints of sudden acceleration for the Lexus and Camry in the 2002-04 model years averaged 132 a year. That's up from an average of 26 annually for the 1999-2001 models, the Times review found.

The average number of sudden acceleration complaints involving the Tacoma jumped more than 20 times, on average, in the three years after Toyota's introduction of drive-by-wire in these trucks in 2005. Increases were also found on the hybrid Prius, among other models.

But Toyota consistently has held that electronic control systems, including drive-by-wire, are not to blame.

"Six times in the past six years, NHTSA has undertaken an exhaustive review of allegations of unintended acceleration on Toyota and Lexus vehicles," Toyota said in a statement earlier this month. "Six times the agency closed the investigation without finding any electronic engine control system malfunction to be the cause of unintended acceleration."

NHTSA officials consistently have said they have not found any electronic defects. "In the high-speed incidents, which are the type of crashes in which death or serious injury is most likely, the only pattern NHTSA has found to explain at least some of them are pedal entrapment by floor mats," a spokeswoman said in a written statement.

Toyota has been under a spotlight since the San Diego crash, in which the driver's desperate efforts to stop the car were recorded on a 911 emergency call made by a passenger. Following that incident, the Times reported that sudden acceleration events involving Toyota vehicles have resulted in at least 19 deaths since the introduction of the 2002 model year. By comparison, NHTSA says all other automakers combined had 11 fatalities related to sudden acceleration in the same period.

Independent electronics and engineering experts say the drive-by-wire systems differ from automaker to automaker and that the potential for electronic throttle control systems to malfunction may have been dismissed too quickly by Toyota and federal safety officials. Unlike mechanical systems, electronic throttles — which have the look and feel of traditional gas pedals — are vulnerable to software glitches, manufacturing defects and electronic interference that could cause sudden acceleration, they say. "With the electronic throttle, the driver is not really in control of the engine," said Antony Anderson, a UK-based electrical engineering consultant who investigates electrical failures and has testified in sudden-acceleration lawsuits. "You are telling the computer, ‘Will you please move the throttle to a certain level?' And the computer decides if it will obey you."

Although Toyota says it knows of no electronic defects that would cause a vehicle to surge out of control, it has issued at least three technical service bulletins to its dealers warning of problems with the new electronic throttles in the 2002 and 2003 Camry.

The throttle systems on six-cylinder engines can cause the vehicle to "exhibit a surging during light throttle input at speeds between 38 miles per hour [61 kilometres per hour] and 42 miles per hour [67 kilometres per hour]," according to one of the bulletins that was published by Alldata, a vehicle information company.

Petitions

NHTSA, the nation's primary agency for auto safety, has conducted a total of eight investigations of unintended acceleration in Toyota vehicles since 2003, prompted by defect petitions from motorists and its own examination of complaints. But the agency has tested electronic throttle systems only twice in those probes, its records show.

Three years ago, the agency asked Toyota to test an electronic throttle component from a 2006 Camry, a task the company delegated to the Japanese supplier that manufactured the part. The supplier exonerated the throttle, and then NHTSA allowed Toyota to keep the 74-page report almost entirely confidential. The report, posted on the agency's website, has dozens of redacted pages.

The other test, conducted at an NHTSA laboratory in Massachusetts, found that a Toyota throttle exhibited unusual behaviour when researchers applied a magnetic field to the device's sensitive electronics. Engine speed surged by 1,000 revolutions per minute, according to a 2008 report by the agency's Vehicle Research and Test Centre.

Nonetheless, the lab concluded that the system "showed no vulnerabilities to electric signal activities." The details of the experiment were not explained in the lab report, and the agency never explained the apparent contradiction.

The electronic throttle was introduced by BMW in 1988. Like a conventional throttle system, it controls the flow of air into the engine. Today, every new Toyota vehicle sold in the US uses drive-by-wire. The systems cost less to install on the assembly line and increase the efficiency of the vehicle. The operations of the systems are opaque to consumers, as are potential failures.

In a worst-case scenario, consultant Anderson says, stray electrical voltages, electromagnetic signals or bad sensor readings could cause an undetectable error within the car's network of up to 70 microprocessors, setting off an unpredictable chain of reactions. One of those, he said, could be a command to completely open the throttle.

The auto industry has battled allegations of electronic defects in sudden-acceleration lawsuits for more than two decades, arguing that they are not caused by any vehicle defect.

Richard Schmidt, a former University of California, Los Angeles, psychology professor and consultant specialising in human motor skills, said the problem almost always lies with drivers who step on the wrong pedal.

"When the driver says they have their foot on the brake, they are just plain wrong," Schmidt said. "The human motor system is not perfect and it doesn't always do what it is told."

To be sure, the complaints by Toyota and Lexus owners about sudden acceleration involve a tiny share of the company's vehicles on the road.

But runaway acceleration represents a high proportion of the complaints filed by consumers about Toyota in federal databases.

Critics say NHTSA hasn't kept pace with technological changes.

The auto industry has undergone a technological revolution in the past decade, and today about 25 per cent of a vehicle's price reflects its electronics content. Nonetheless, NHTSA has adopted few, if any, standards for designing or testing vehicle electronics, according to industry officials. The agency's two-page safety standard for accelerators was adopted in 1973.

Dale Kardos, who runs a consulting company that helps automakers with regulatory issues, said that manufacturers have repeatedly tried to get that standard updated because they fear they can no longer comply. "The industry would like to see standards written to reflect modern technology," Kardos said.

Instead, independent organisations and the industry itself are setting standards and developing safety policies. The International Organisation for Standardisation, a non-governmental group that sets industrial standards, recently introduced a new standard for automakers to protect vehicle electronics.

Standards

"Manufacturers' standards are far above the regulatory standards," said Ian Harvey, TRW Automotive Holdings' executive lead for electro-mechanical compatibility. "You wouldn't want somebody to make a cell phone call and the air bag goes off. That potentially could happen if you didn't take the proper precautions."

Despite the huge increase in complexity, when NHTSA investigators conduct field tests of alleged malfunctions of Toyota throttle systems, they rarely have done more than drive suspect vehicles for a few miles, test the brakes and plug a diagnostic tool into their onboard computers to look for error codes, investigation records show.

Michael Pecht, a professor of mechanical engineering at the University of Maryland who has studied sudden acceleration for 10 years, said it's nearly impossible to replicate an electronic control system fault simply by driving a short distance. "These are not things that occur every day. If it occurred a lot, you could track it down. If it occurs once in 10,000 trips, then it is difficult to find," he said.

Toyota announced on Wednesday that it had developed a series of fixes to prevent floor mats from causing sudden acceleration.

Independent auto safety experts said that although Toyota's fixes will help reduce the problem, it has not got to the root. "These incidents are coming in left and right where you can't blame the floor mats," said Sean Kane, president of the consulting company Safety Research and Strategies. "So they are chipping away at a problem that is widespread and complicated without having to unravel a root cause that could be very expensive."

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