Toyota has always maintained that its unintended acceleration problems are mechanical in nature. If it wasn't a bunched-up floor mat it's a sticky gas pedal. Customers and regulators have their own theories however. They suspect the electronic throttle control, or ECT.
In modern cars like the Prius, there is no physical connection between the gas petal and the engine. Instead of a cable that connects the pedal to the throttle, there's an electronic sensor that measures how far the gas pedal is to the floor and sends that information to a computer which, in turn, tells the motor how high to rev. It's called drive-by-wire.
Such a Rube Goldberg set-up makes goodies like cruise control, traction control, stability control, and pre-crash systems just a matter of programming. Indeed, by some estimates there are as many lines of code in a modern car as there are in the operating system of the computer you're reading this on.
That's great - until things start to go wrong. Why couldn't a software bug in the drive-by-wire have caused the sudden acceleration problems? After all, computers crash all the time.
So far, Toyota's response has boiled down to "trust us, its a mechanical failure." There is no way to verify this, because the actual programming - the code that controls the gas pedal as well as those other nifty features- is a trade secret.
But "trust us" is clearly not cutting it with the consumers or the media. On the chat forums, it's easy to find conspiracy-minded types who think that the investigators that Toyota has sent to investigate the high-profile incidents are actually erasing pre-crash data. What's more, the Associated Press recently conducted an investigation that found that a germ of truth in this paranoid accusation.
There is really only one way to clear the air, and that's for Toyota to release its software code, letting anyone who is interested download it and test it themselves. The loss of a few trade secrets is surely worth what the company will gain in consumer confidence. In business as in politics, sunshine is the best disinfectant.