Automotive Tips: What Exactly is "Drive-by-Wire"?

Every so often it seems, an industry gets stuck on a certain word and term and uses it relentlessly. Recently, the term "drive-by-wire" has become a favorite in the automotive world. Many car companies claim proudly that their vehicles feature the technology, and that it is a great improvement over traditional systems. However, this may leave some who aren't exactly car buffs wondering what the term really means,

One might be somewhat surprised to learn that drive by wire technology really isn't that new. The idea has been used by the military for a while, and it even began finding its place on luxury cars in the mid to late 1990's.

Drive by wire really comes down to a pretty simple idea. In a conventional car, a cable controls the throttle of the engine. Thus, connecting the gas pedal directly to the throttle. However, drive by wire replaces that cable, giving the driver electronic control of the throttle.

In order to simplify this idea, think of the volume knob on a stereo. Now imagine that knob connected to a cable going from the gas pedal to the engine of your car. Drive by wire is actually very simple when it's broken down. The position of the knob indicates how much power the engine is going to use during a given cycle. In practice, the idea works very similar to the traditional pedal-cable-throttle approach, but there are a few benefits to gain from using it.

Namely, the computer system eliminates the possibility of human error, leaving the practice to electronics. Which, to some, might actually sound a bit worrisome. After all, if the system fails, would that place the car on a high speed runaway to destruction? Of course not, and drive by wire has undergone extensive testing in order to make sure that even if the system did fail, the engine would simply lose power as opposed to becoming a runaway terror.