Toyota was in the hot seat of a Congressional hearing Tuesday, and the sizzling testimony was highly unlikely to lead to any resolution or catharsis. Instead, it is leading Toyota straight off a cliff.

An impasse has been reached, with victims, their lawyers and some independent experts claiming that electronic interference is causing sudden acceleration, and Toyota (with some backing from the federal safety agency) is saying just as forcefully that it is ruling out such causes. But these incidents keep happening, and they won’t be contained by Toyota’s recalls — which address sticking pedals and interfering floor mats.

Rhonda and Eddie Smith of Sevierville, Tenn., a couple with two grandchildren and a 38-year marriage, probably never thought they’d be testifying in front of Congress, but they didn’t expect their Lexus ES 350 to run away, either. Rhonda Smith told Congress she was on her way to visit her 85-year-old father in Knoxville when “I lost all control of the acceleration of the vehicle.”

Going beyond other accounts, Smith said that the brakes had no effect, and putting the car into neutral and even reverse did not slow it down, either. “After about three miles had passed, I thought it was my time to die,” she said. "I prayed for God to help me." The car finally began to slow down after six miles, Smith said. But even after being shut down, she claims it attempted to start again. Toyota’s representatives told her the problem was floor mat interference, and all claims were denied.

Several other victims attended the hearings, and some talk about their experiences in this video:

Experienced auto hands have a hard time believing that a Lexus ES 350 would start by itself or refuse to go into neutral, which is probably why the initial impulse was to blame driver behavior. (In a National Center for Dispute Settlement hearing, a Lexus rep told Smith that she had probably been “standing on the brakes while spinning the tires.”)

But other testimony on Tuesday is starting to make clear how electronic interference could cause sudden acceleration. Although Toyota Motors Sales CEO and President Jim Lentz said, “We are confident that no problems exist with the electronic throttle control system in our vehicles” (his mantra all along), there was compelling testimony otherwise.

David Gilbert, a professor with a Ph.D. in automotive technology at Southern Illinois University in Carbondale, has been a technical educator working with auto diagnostics for 30 years. Working with a 2010 Toyota Tundra he bought, Gilbert pursued his own investigation, and he said in his testimony, “My initial findings question the integrity and consistency of Toyota Electronic Control Modules (ECM) to detect potential electronic throttle control system circuit malfunction.”

To understand this you have to know that there’s no physical connection between your foot pressing on the gas pedal and the engine accelerating — it’s done by electronic signals between sensors on the pedal and the ECMs. The systems are redundant — there are two sensors, and each signal is supposed to agree with that of its companions, or the system goes into “fail safe” mode and the engine idles.

Gilbert is saying that he found that malfunctions could be introduced that do not set a diagnostic trouble code, and therefore do not trigger “fail-safe” mode. He says that when the two sensors shorted together, “all four Toyota vehicles tested thus far reacted similarly and were unable to detect the purposely induced abnormality,” nullifying the value of the redundant circuit design. “The condition then exists for a serious concern for driver safety,” he said.

These conclusions were echoed by Sean Kane, president of Safety Research & Strategies, a spinoff of the Nader-connected Center for Auto Safety. Kane said in his testimony that nearly half of the 2,263 Toyota complaints the firm studied involved vehicles outside of the company recalls. “Random, intermittent electronic faults are hard to detect, but they do occur,” he said. “Toyota and the regulators must look more closely at the vehicle control systems, including the electronic throttle control assembly and the associated sensors.”

Transportation Secretary Ray LaHood remains skeptical about electronic causes, though he said in his own remarks that the National Highway Traffic Safety Administration (NHTSA) is conducting a review of electronic systems on cars. “This is a review of the technological issue, not a defect investigation,” he said, adding that such an investigation could occur later if evidence warrants it.

For their parts, Toyota’s president, Akio Toyoda, and the company’s U.S. CEO, Yoshimi Inaba, apologized profusely but stuck to the script: We’re working on it, we’re “taking decisive steps,” and conducting a “top-to-bottom review.” But neither said anything about electronic causes, which the automaker has tried to refute in conference calls with journalists in recent days.

Henry Waxman, chairman of the House Committee on Energy and Commerce, was direct in detailing Toyota’s failings. “There is no evidence that Toyota or NHTSA took a serious look at the possibility that electronic defects could be causing the problem,” he said in opening remarks.

So, for now, the Toyota crisis will continue.

MNN homepage photo: Mark Wilson/Getty Images

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

In sizzling Congressional testimony, Toyota takes flak for electronic interference
Appearing before a House committee, Toyota stuck to its line about sticky pedals and floor mats, but investigators, victims and expert witnesses aren't buying i