Electronics are not to blame for Toyota acceleration problem

09 February 2011

The US Department of Transportation has released the results from a ten-month study of potential electronic causes of unintended acceleration in Toyota and Lexus vehicles. NASA engineers evaluated the electronic circuitry in the affected vehicles and analysed more than 280,000 lines of software code in its thorough search for potential flaws and errors.

The National Highway Traffic Safety Administration (NHTSA) launched the study last spring at the request of Congress, and enlisted NASA engineers with expertise in areas such as computer controlled electronic systems, electromagnetic interference and software integrity to conduct new research into whether electronic systems or electromagnetic interference played a role in incidents of unintended acceleration.

NASA engineers found no electronic flaws in Toyota vehicles capable of producing the large throttle openings that are required to create dangerous high-speed unintended acceleration incidents.

The two mechanical safety defects identified by NHTSA more than a year ago – ‘sticking’ accelerator pedals and a design flaw that enabled accelerator pedals to become trapped by floor mats – remain the only known causes for these unintended acceleration incidents. Toyota has recalled nearly 8 million vehicles in the United States for these two defects.

US Transportation Secretary Ray LaHood said: “We enlisted the best and brightest engineers to study Toyota’s electronics systems, and the verdict is in. There is no electronic-based cause for unintended high-speed acceleration in Toyotas."

In conducting their report, NASA engineers evaluated the electronic circuitry in Toyota vehicles and analysed more than 280,000 lines of software code for any potential flaws that could initiate an unintended acceleration incident.

At the Goddard Space Flight Center in Maryland, NASA hardware and systems engineers rigorously examined and tested mechanical components of Toyota vehicles that could result in an unwanted throttle opening.

At a special facility in Michigan, NHTSA and NASA engineers bombarded vehicles with electromagnetic radiation to study whether such radiation could cause malfunctions resulting in unintended acceleration. NHTSA engineers and researchers also tested Toyota vehicles at NHTSA’s Vehicle Research and Test Center in East Liberty, Ohio, to determine whether there were any additional mechanical causes for unintended acceleration and if any of the test scenarios developed during the NHTSA-NASA investigation could actually occur in real-world conditions.

"NASA found no evidence that a malfunction in electronics caused large unintended accelerations," said Michael Kirsch, Principal Engineer at the NASA Engineering and Safety Center (NESC).

While NASA and NHTSA have identified no electronic cause of dangerous unintended acceleration incidents in Toyota vehicles or any new mechanical causes beyond sticking pedals and accelerator pedal entrapment, NHTSA is considering taking several new actions as the result of these findings, including:

• Propose rules, by the end of 2011, to require brake override systems, to standardise operation of keyless ignition systems, and to require the installation of event data recorders in all passenger vehicles

• Begin broad research on the reliability and security of electronic control systems

• Research the placement and design of accelerator and brake pedals, as well as driver usage of pedals, to determine whether design and placement can be improved to reduce pedal misapplication

NHTSA and NASA will also brief the National Academy of Sciences panel currently conducting a broad review of unintended acceleration and electronic throttle control systems on the reports released.

“While today marks the end of our study with NASA, our work to protect millions of American drivers continues,” said NHTSA Administrator David Strickland. “The record number of voluntary recalls initiated by automakers last year is also very good news, and shows that we can work co-operatively with industry to protect consumers."

Based on objective event data recorder (EDR) readings and crash investigations conducted as part of NHTSA’s report, NHTSA is researching whether better placement and design of accelerator and brake pedals can reduce pedal misapplication, which occurs in vehicles across the industry.

NHTSA’s forthcoming rulemaking to require brake override systems in all passenger vehicles will further help ensure that braking can take precedence over the accelerator pedal in emergency situations.

The ongoing National Academy of Sciences study, which will examine unintended acceleration and electronic vehicle controls across the entire automotive industry, will also make recommendations to NHTSA. The NAS study was launched in spring 2010 alongside the NHTSA-NASA investigation and will be finalised later in 2011.

In 2009 and 2010, Toyota recalled nearly eight million vehicles as part of the ‘sticky pedal’ and pedal entrapment recalls. Toyota also paid $48.8 million in civil penalties as the result of NHTSA investigations into the timeliness of several safety recalls last year.

When NHTSA first identified the two defects more than a year ago, the agency pushed Toyota to conduct recalls quickly. Toyota later paid nearly $33 million in civil penalties as the result of investigations into whether the company notified NHTSA in a timely manner about these defects.

During Congressional hearings on the Toyota recalls in February 2010, Members of Congress asked NHTSA to study whether electronic or software problems in Toyota vehicles could be to blame for unintended acceleration.

NHTSA Administrator David Strickland
NHTSA Administrator David Strickland

At Congress’ request, NHTSA simultaneously launched two studies; one designed to evaluate possible electronic causes for unintended acceleration in Toyotas, and a broader effort to look at unintended acceleration across the automotive industry.

In March 2010, NHTSA enlisted NASA engineers and experts in areas such as electromagnetic compatibility to study whether electronic flaws can cause unintended acceleration.

In its final report, NASA engineers found no evidence of an electronic defect in Toyota vehicles capable of producing dangerous, high-speed unintended acceleration incidents.

The two mechanical safety defects originally identified by NHTSA remain the only known causes of dangerous unintended acceleration incidents.

Nevertheless, NHTSA has announced several new actions it may take as a result of their work with NASA to address the safety of vehicle electronics systems. NHTSA will consider rules to require brake override systems, standardise operation of keyless ignition systems, and require the installation of event data recorders in all passenger vehicles.

NHTSA will conduct broad research on the reliability of electronic throttle control systems across the vehicle fleet. The agency will also initiate new research on driver behaviour and the placement and design of floor pedals in an effort to identify strategies that can reduce pedal misapplication.

The second study launched by US DOT in March 2010 remains under way. The Department has enlisted the prestigious National Academy of Sciences (NAS) to undertake a broad review of unintended acceleration and electronic vehicle controls across the automotive industry. An independent panel of scientific experts at NAS is currently working to identify possible sources of unintended acceleration, including electronic vehicle controls and human error.

Later in 2011, the panel will make recommendations to NHTSA on how its rulemaking, research, and defect investigation activities can help ensure the safety of electronic control systems in motor vehicles.

In response to the publication by the NHTSA of an extensive review of the electronic throttle control systems in Toyota and Lexus vehicles, conducted with the assistance of the National Aeronautics and Space Administration, Steve St. Angelo, Toyota’s Chief Quality Officer for North America, said: “Toyota welcomes the findings of NASA and NHTSA regarding our Electronic Throttle Control System with intelligence (ETCS-i) and we appreciate the thoroughness of their review. We believe this rigorous scientific analysis by some of America's foremost engineers should further reinforce confidence in the safety of Toyota and Lexus vehicles. We hope this important study will help put to rest unsupported speculation about Toyota's ETCS-i, which is well-designed and well-tested to ensure that a real world, un-commanded acceleration of the vehicle cannot occur. We will continue to develop and equip Toyota and Lexus vehicles with industry-leading safety technologies, including many based on breakthroughs in sophisticated electronics systems. We will also continue to co-operate fully with NHTSA and respected outside experts in order to help ensure that our customers have the utmost confidence in the safety and reliability of our vehicles. Everyone at Toyota – all 30,000 of our team members in the United States and the many thousands of Americans at our dealers and suppliers across the country – is focused on listening to our customers and constantly improving our products and service.”

Regarding the safety and reliability of Toyota vehicles with ETCS-i, the company also noted:

• Electronic throttle control systems have long been standard across the automobile industry, and they provide benefits to consumers

• Toyota’s ETCS-i has performed reliably in more than 40 million cars and trucks sold around the world, including more than 16 million in the United States

• This system has also made possible significant safety advances such as vehicle stability control and traction control, which are among the five sophisticated accident avoidance technologies in Toyota’s Star Safety System

• These enhancements, along with Toyota’s Smart Stop Technology braking system, are now standard on all the new vehicles Toyota manufactures for the North American market

Timeline of events

29 March 2007

NHTSA opens a preliminary investigation into pedal entrapment on 2007 model year Lexus ES350 models based on five consumer complaints alleging three crashes and seven injuries. The all weather floor mat is identified as the possible cause of these incidents.

26 July 2007

A fatal crash occurs in San Jose, involving a 2007 Camry, in which the driver suffers serious injuries and the driver of the struck vehicle is killed. The incident also appears to have been caused by a pedal trapped by an all weather floor mat.

13 September 2007

After determining the fatal San Jose crash was caused by floor mat entrapment, NHTSA tells Toyota that a recall is necessary.

26 September 2007

Toyota recalls 55,000 floor mats in 2007 and 2008 Camrys and ES350s.

2007 Toyota Camry. Image courtesy of Toyota
2007 Toyota Camry. Image courtesy of Toyota

28 August 2009

A fatal crash occurs in Santee, involving a 2009 ES350. The vehicle is found to have an all weather floor mat from another Lexus vehicle. Investigators find that the vehicle’s previous driver had reported an entrapment incident to the dealership.

25 September 2009

NHTSA meets Toyota and tells the company that the floor mat recall is insufficient and the agency expects a recall for the defect in pedal design. Three days later, Toyota tells NHTSA that the company will recall the accelerator pedals.

5 October 2009

Toyota recalls 3.8 million vehicles for pedal entrapment by floor mat and sends an interim letter to consumers telling them to remove floor mats. The defect remedy involves pedal reconfiguration, floor pan/carpeting revisions, and ‘brake pedal override’ software for vehicles with keyless ignition.

15 December 2009

NHTSA officials meet Toyota executives in Japan to explain NHTSA’s defect recall process and underscore Toyota’s obligations under US law to find and report defects promptly. Toyota commits to making improvements.

16 January 2010

Toyota informs NHTSA that certain CTS-brand pedals may have a dangerous ‘sticking’ defect. NHTSA calls an in-person meeting on 19 January.

19 January 2010

At the meeting, Toyota provides field reports on sticky pedal incidents, and NHTSA tells Toyota that the agency expects prompt action. Toyota informs NHTSA several hours later that the company will issue a recall.

21 January 2010

Toyota recalls 2.3 million vehicles for the sticky pedal defect.

27 January 2010

At NHTSA’s urging, Toyota expands its pedal entrapment recall to cover an additional 1.1 million vehicles.

16 February 2010

NHTSA launches an official probe into the timeliness and scope of the pedal entrapment and sticky pedal Toyota recalls.

30 March 2010

At the request of Congress, the US DOT announces two studies into unintended acceleration. One looks at possible electronics causes for unintended acceleration in Toyotas; the other examines unintended acceleration and the safety of vehicle electronics across the automotive industry.

5 April 2010

NHTSA demands the maximum, $16.375 million civil penalty on Toyota for its failure to notify the agency of the sticky pedal defect for more than four months after discovering it. Auto manufacturers are legally obligated to notify NHTSA within five business days of determining that a safety defect exists. Toyota pays the full fine on 19 April.

20 December 2010

Toyota agrees to pay the maximum $16.375 million civil penalty as the result of another NHTSA investigation into whether their recall of 5.5 million vehicles for pedal entrapment was conducted in a timely manner.

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