Acceleration Case: Jury Finds Toyota Liable

It wasn't loose floor mats or a sticky pedal that caused the sudden acceleration of a 2005 Camry in an accident that killed one woman and seriously injured another on an Oklahoma highway off-ramp in September 2007. The electronic throttle control system did it.

This was the closing argument of the plaintiffs' attorneys. In contrast, attorneys for Toyota blamed the crash on driver error.

In a verdict delivered Thursday afternoon, an Oklahoma County jury found Toyota's in-car technology liable for the crash.

The Associated Press reportsthat the jury awarded $1.5 million in monetary damages to Jean Bookout, the driver of the car, who was injured in the crash, and $1.5 million to the family of Barbara Schwarz, who died. The jury also decided Toyota acted with "reckless disregard" for the rights of others. A second phase of the trial on punitive damages is scheduled to begin Friday.

Bellwether

Experts had viewed the Oklahoma case -- one of several hundred contending that the company's vehicles tended to accelerate inadvertently -- as a bellwether. This was the first test of a claim that put the fault squarely on a flaw in the vehicle's electronic throttle control system. Embedded systems experts who reviewed Toyota's electronic throttle source code testified that they found it defective. They said it contains bugs -- including some that can cause unintended acceleration.

It's important to note, however, that Toyota's electronics throttle control system had already been the subject of a NASA investigation that reportedly found no electronic causes of unintended acceleration. After the US space agency's 10-month investigation, the National Highway Traffic Safety Administration closed its probe of Toyota models in February 2011.

But not everyone in the embedded systems industry thinks NASA had enough time to come up with a complete report. Perhaps more significantly, in its report,NASA itself did not rule outthe possibility of software having caused unintended acceleration.

The NESC team identified two hypothetical ETSC-i failure mode scenarios (as opposed to non-electronics pedal problems caused by sticking accelerator pedal, floor mat entrapment, or operator misapplication) that could lead to[an unintended acceleration]without generating a diagnostic trouble code (DTC): specific dual failures in the pedal position sensing system and a systematic software malfunction in the main central processor unit (CPU) that is not detected by the monitor system...

The second postulated scenario is a systematic software malfunction in the Main CPU that opens the throttle without operator action and continues to properly control fuel injection and ignition...

Because proof that the ETSC-i caused the reported UAs was not found does not mean it could not occur.

For the Oklahoma trial, a new group of embedded systems experts was hired to dig deeper in hopes of picking up where NASA left off. However, how exactly a single bit flip could cause the driver of a real car to lose control of the engine speed demands more detailed explanation from experts.

EE Times will be talking to some who were involved in the investigation, and we will be breaking down what went wrong -- according to experts -- with Toyota's electronic throttle control systems. These experts are currently under a gag order from District Judge Patricia Parrish, who ordered attorneys and experts on both sides not to discuss the case publicly until after the punitive stage.