Defining Electronic Stability Control (ESC)

Researching any vehicle you are seriously considering purchasing should include an evaluation and comparison of the vehicle's safety and security features. Some vehicles may offer an extensive and well written list of safety features, but if that list does not include the most highly regarded and recommended safety features, its length is of little significance. Electronic Stability Control (ESC) is an extension of both anti-lock brakes and traction control systems and is exceptionally effective. The National Highway and Traffic Safety Administration has already announced its intention to require all auto manufacturers to include ESC as part of the standard equipment list for each and every vehicle by the start of the 2012 model year.

ESC helps to maintain the direction of the vehicle if it should begin to drift beyond the driver's intended path. For example, if the driver misjudges the speed reduction required when entering a sharp curve in the road, there is a good chance the vehicle could slide or skid out of control. To prevent the vehicle from rolling over or spinning out of control, the electronic stability control system takes over and sends individual or a combination of computerized commands, as needed and applicable for the situation, that force the application of the brakes to an individual or multiple wheels and/or reduce engine throttle. This reduction in engine power enables maximum traction and helps keep the vehicle under control and on course.

ESC uses a computer that communicates with a series of sensors that detect the wheel spin, steering angle, wheel speed and sideway motion. ESC does not actually increase the available traction, but it does highly increase the chances of keeping the vehicle on the road and under control in high risk circumstances.

Electronic Stability Control is activated in the events of understeer and oversteer, as in the examples. The left panel shows a front-end skid rounding a left-hand curve in which the front wheels lose traction. To gain traction, the ESC system applies braking to the left rear wheel. The right panel shows a rear-wheel skid being corrected by the ESC system applying braking to the right front wheel. An elegant and effective system.

Quite a few manufacturers have enhanced their electronic stability control systems with technology that works to further alleviate the chances of roll over on their SUV lines, which have a higher chance of roll over than most other vehicles during the execution of extreme driving maneuvers. Of course, safe driving is encouraged and ESC does not guarantee its intended results. Heading in to any corner or curve in the road at too fast a speed can compromise the ability of the electronic control system to keep the vehicle on its directed path.

In addition to ESC, electronic stability control systems have many other manufacturer assigned trade names including and Vehicle Stability Enhancement (VSE), Electronic Stability Program (ESP) and Vehicle Stability Control (VSC). There are actually more than 10 different and proprietary names and acronyms in the automotive industry for electronic stability control, which can be very confusing to consumers. Most manufacturers, such as in the case of the Lexus Rx-400h, use the correct acronym. In an effort to make identifying this feature easier and encourage industry standard terminology, the Society of Automotive Engineers has requested that all manufacturers that offer this feature refer to it as electronic stability control or ESC. Until this request has been granted, be sure to ask the dealer if you are unsure if ESC is part of the vehicles standard equipment or available as an option.