While the massive recall of Toyota Motor Corp. vehicles for faulty accelerator pedals is focusing on a plastic friction device within the pedal assembly, which the company says can “stick” under certain conditions, transportation and safety officials are widening their investigation into car electronics.
Toyota halted sales of many of its most popular brands in the U.S. and has recalled 2.3 million vehicles dating back to the 2005 model year to fix the problem, which can result in sudden acceleration.
In letters to the U.S. National Highway Traffic Safety Administration and in public statements, Toyota said it pinpointed the issue to devices within the pedal assembly.
Most vehicles made today use electronic throttle control. But to give drivers the feel of the old cable systems, Toyota and other carmakers use springs and a friction device within the assembly. In these pedals, supplied by CTS Corp. of Elkhart, Ind., the friction device is made of two plastic parts that slide against each other. Toyota has used polyphenylene sulfide in models made since 2008 and nylon 4/6 in earlier models, Toyota said in documents filed with NHTSA.
“Due to the materials used, wear and environmental conditions, these surfaces may, over time, begin to stick and release instead of operating smoothly,” Toyota Motor Sales USA Inc. said in a Feb. 1 news release. “In some cases, friction could increase to a point that the pedal is slow to return to the idle position or, in rare cases, the pedal sticks, leaving the throttle partially open.”
However, U.S. Transportation Secretary Ray LaHood said Feb. 3 that NHTSA's probe is continuing, with the agency looking carefully at electronic controls for all vehicles, starting with Toyota's system.
Members of the U.S. House of Representatives echoed the concerns over electronic controls. In a Feb. 2 letter to Jim Lentz, president and chief operating officer of Toyota Motor Sales U.S.A. Inc., congressmen Henry Waxman of California and Bart Stupak of Michigan raised questions about the electronic operating system, and asked Lentz to provide any evidence Toyota has to back up claims that the issue has nothing to do with electronics.
The letter cited a Jan. 27 meeting with Toyota staff and the House Committee on Energy and Commerce staff.
“At that meeting, Toyota officials indicated that sticking accelerator pedals are unlikely to be responsible for the sensational stories of drivers losing control over acceleration as their cars race to 60 miles per hour or higher,” the letter stated.
“The officials said that condensation buildup in a 'sticky pedal' can cause the accelerator to become lodged in a slightly depressed position, but they said this would not lead to full-throttle acceleration.”
The congressmen asked that Toyota provide further evidence on the issue to the committee by no later than Feb. 12 and to respond by Feb. 5.
The announcement has prompted some negative global attention for an automaker that built its reputation on reliability and safety. Toyota also has said that up to 1.8 million vehicles across Europe may be affected and expects to begin repairs there as well.
In a Jan. 21 letter to NHTSA, Toyota stated it first received field reports of accelerator pedals being slow to return to the idle position in March 2007. The reports involved only one vehicle at that time, the Tundra pickup truck, which used nylon 4/6 in the friction lever.
Its investigation at that time indicated the materials were “susceptible to humidity,” which could cause the lever to absorb moisture and swell.
In February 2008, the firm said, it switched the nylon 4/6 to PPS, which was used in other pedal systems by other carmakers.
In December 2008, Toyota began receiving field reports from Europe about problems with a PPS pedal system on European-made Aygo and Yaris vehicles, but concluded the problem was only on right-hand drive vehicles without air-conditioning systems. The company changed the design and began producing pedal systems using a longer lever arm in the friction system in August 2009 in Europe.
It began receiving field reports in the U.S. and Canada of problems with PPS pedal systems in a variety of vehicles in October 2009. Its investigation eventually led to the recall at the end of January 2010.
The automaker will place a specially designed steel reinforcement bar between the two plastic surfaces to reduce excess friction. Both Toyota and NHTSA have said they know of no deaths or injuries related to the problem.
The pedal-friction issue is a separate recall from an earlier issue in which floor mats could become jammed under pedals. Toyota issued a recall to fix that problem in late 2009. There have been fatal crashes linked to floor mats.
Toyota, which is based in Toyota City, Japan, and has North American offices in Torrance, Calif., also acknowledged problems with the brake system in its most recent model of the Prius hybrid, although it has not launched any recalls related to it. NHTSA opened its own investigation on the brakes Feb. 4.
Washington is not the only place generating questions about the electronics. Steve Wozniak, who co-founded Apple computers, went public with his complaints about sudden acceleration. In interviews with several media outlets, he said his Toyota Prius will accelerate when it is in cruise control, with his foot off the pedal.
Prius is not on the list of recalled cars.
Wozniak stated that he believes the problem is related to software. Toyota is taking a closer look at Wozniak's car, but in public statements has maintained that the problem is due solely to issues with the pedal itself.
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