Electronic Stability Control (ESC) is a computer that takes over control of the vehicle when the vehicle’s path is not what the driver intended it to be. For those of us who have lost control of a car, we know that it’s that first twitch of the car that tells us that we are about to have an exciting experience. That twitch is information the car is sending to us. For some, interpreting this information is second nature, and for others, it’s like trying to understand Swahili. That sinking feeling we get in our stomach is the car telling us that it’s not going where we want it to go, but it is going on a path that it wants to go. The value of ESC is that it interprets the information, in most cases, before the average driver or even the above average driver can sense the problem. Once the ESC computer reads the information it starts to set the car on the correct path before we can figure out what’s going on.
HOW IT WORKS
Electronic Stability Control uses the existing ABS and Traction Control computers, plus additional sensors to monitor what the car is doing after you tell it what to do. By measuring throttle position, steering wheel angle and lateral acceleration, the computer compares the intended path of the vehicle to the path the car is actually taking. If it’s not doing what you wanted it to do, or if what you are doing is contrary to good sense and the laws of physics, the ESC computer takes over. When ESC decides to handle the driving chores it applies one of the front brakes, or in some systems one of the front and/or rear brakes, to straighten the car and put it back on the path you wanted it to go.
Of course, there are limits to the effectiveness of stability control. It makes it a bit more difficult to do J-Turns. The computer is sensitive to weight, so that needs to be taken into consideration. If your vehicle becomes stuck in deep snow, for example, automakers generally advise that you turn off stability control—there’s usually a deactivation button on the dashboard—in order to get the full power of the engine and wheel spin as you try to work your vehicle free. Also, computers cannot overcome stupidity. ESC cannot compensate if the driver is driving far beyond road and vehicle conditions. In other words, it’s not a license to drive like an idiot.
IT SAVES LIVES
It’s no exaggeration to say that stability control is the biggest automotive safety advancement since ABS and airbags. Researchers at the Insurance Institute for Highway Safety found that ESC reduces the risk of fatal multiple-vehicle crashes by 32 percent. The new research confirms that ESC reduces the risk of all single-vehicle crashes by more than 40 percent—fatal ones by 56 percent. The researchers estimate that if all vehicles were equipped with ESC, as many as 10,000 fatal crashes could be avoided each year.