Since 1999, there have been at least 2,262 reports by Toyota and Lexus owners of sudden unintended acceleration in their vehicle under a variety of circumstances. Now known as SUA amongst the National Highway Traffic Safety Association (NHTSA), courts, Safety Research & Strategies and media sources, instances of sudden unintended acceleration has resulted in 815 crashes, 341 injuries and 19 deaths where SUA potentially played a role.
A prominent issue is that neither Toyota nor the NHTSA have been able to identify all of the causes of SUA that have occurred in Toyota and Lexus models over a span of many years in a variety of makes and models. The struggle to locate the defective auto part or problem has delayed a consistent remedy that addresses the complaints of consumers.
In 2003, the NHTSA began its first of 8 investigations into SUA causes in Lexus models and Toyota's Camry, Tacoma, and Sienna models. Although three of these investigations determined that all-weather accessory floor mats or vehicle trim interfered with accelerator pads, the other five investigations failed to identify a definite cause of SUA. Toyota initially placed blame on customers for installing floor mats improperly, taking no other action to determine the causes of SUA.
2005 and 2007 saw two small recall campaigns: The first corrected an accelerator that stuck in Lexus IS251 vehicles, the second replaced all-weather floor mats in limited quantities of 2007 and 2008 Lexus and Camry vehicle models. With public pressure weighing in, large recalls have taken place more recently. These recalls redesigned floor mats, shortened accelerator pedals and installed a break override feature.
Unfortunately, the automakers have been slow to accept responsibility for the design flaws and safety hazards that affect the many drivers of their vehicles, as well as others on the road when accidents occur. The possible flaws that have been identified are floor mats and floor mat arrangement on the driver's side, the pedal mechanism, the pedal placement or a combination of these problems. Although accelerator pedals that are slow to return to the idle position requires repair, it has not been linked to cause SUA.
Complaint data has shown that replacing the sticking pedal or floor mat does not resolve the problem because drivers experience SUA when their vehicle is in idle mode, when the foot is on the brake, when no or properly installed all-weather accessory floor mats are present, and when the driver is maintaining a constant highway speed.
Investigations have not been thorough enough to identify the other causes and completely solve the SUA problem. Some believe that the focus on a mechanical defect is proving fruitless and that investigation into electrical issues is necessary, though automakers have been reluctant to do so, possibly because of a lack of electrical expertise. An investigation of the electrical system in these models may identify electronic causes in the vehicle control systems like electronic throttle control assembly and failsafe systems.
Toyota has argued that their electrical systems are infallible, and cannot be the cause of SUA. However, since no consistent cause has been identified, many speculate that the hard to detect, random, intermittent electronic faults may be linked to SUA. Some of the possible points of breakdown in interruption in the electronic system concern the electrical contacts, electromagnetic interference and the programming of electronic controls.
Though Toyota has failed to do so yet, it is becoming clear that a full examination of SUA must explore the interactions between the mechanical workings of the vehicle and the sophisticated electronic systems that influence them. In the meantime, brake-to-idle features should be installed across all models, lines and years, as the signal to brake will override acceleration even if the throttle is open, allowing the driver to regain control of a runaway vehicle.
About half of the complaints of SUA are from drivers whose vehicles have not been recalled. The issue is still very relevant and it is imperative that automakers act to protect the public from these types of auto defects.
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