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    Time was when the Toyota corporate catch phrase was “Oh, What A Feeling!”  Presumably the marketing wonks were talking about the sublime, self-satisfied feeling of superiority over mere mortal automobiles, not the feeling of white-knuckled panic as your trusty Toyota barrels down the highway at a screaming wide open throttle thrill ride. In August of last year, Noriko Uno of California was killed when her Toyota unexpectedly went ballistic on the freeway. Eyewitnesses reported seeing her Toyota frantically passing other vehicles, desperately weaving in and out of lanes in excess of 100 miles an hour, just before her car became airborne and made a close encounter of the worst kind with a tree. This incident occurred before the current crop of throttle mayhem cases that have made Toyota’s engine control crisis rise to the apex of public and political discussion, and her family has wrongful death litigation pending in the California courts.

    The finger of blame for all of these throttle control malfunctions is currently jabbing at temperamental gas pedals or wandering floor mats- take your pick. When I first heard of the problems that Toyota was having my suspicions were directed to a system that I have had qualms about for a long time - namely the “divorced throttle” arrangement. For the uninitiated, divorced throttle describes a control system where there is no physical connection between the throttle pedal and the device on the engine that controls engine speed. Instead the throttle pedal is reduced to nothing more than a positioning sensor, it sends a graduating signal to the engine control module, which in turn precisely controls throttle opening in relation to pedal travel. (Well, except when Murphy’s Law takes over.)  My initial apprehensions were reinforced when I happened to see an account on television about an intrepid Toyota motorist who recently experienced an uncontrolled throttle event, he coolly bumped his Toyota into neutral after the engine started roaring like the Wabash Cannonball. He then managed to coax his car into a Toyota dealership that just happened to be located directly down the nearest off ramp. While his car sat there in the parking lot with the engine screaming in neutral like a Stuka Dive Bomber, he dragged the service manager out to the car so that all interested parties could see that this was not, in fact, a case of floor mats meandering where they shouldn’t be meandering.

    Separating the vehicle operator from safety systems like throttles and steering with only software and electrons between the two is classic case of ignoring Occam’s Razor, the theorem that the simplest solution for a given problem is almost always the best solution. There is absolutely no substitute for safety and reliability of a cable connection between the vehicle driver and the throttle valve, the never fail mechanical link between the operator’s steering wheel and the wheels on the road. Divorced systems by their very nature require a much higher level of complexity and complex systems fail much more often than simple ones, no matter what level of redundancy is engineered into them in an effort to anticipate every conceivable failure scenario. And the real problem is simply this- failures of these critical automobile safety and control systems are frequently catastrophic and occasionally lethal.

    The good Friar Occam was referring to religious doctrines when he proposed his theorem, but it still lives in engineering. Engineering solutions achieve their highest order precisely when they reach their greatest simplicity.

Bob Sanders

Bob@KarmaKanic.com