What is Electronic Stability Control and How Does It Work?

While shopping for a new car, you've probably come across the term 'electronic stability control' and wondered what it's for. To avoid confusion and to ensure you know what you’re buying, Carmudi provides you with key pieces of information about this extremely helpful safety feature.

What is electronic stability control?

Electronic stability control (ESC)--also known as electronic stability program (ESP) or dynamic stability control (DSC)--is a system that keeps the vehicle on the path that the driver wants to go. So when your car starts to swerve away from your intended path, the system will stabilize your car to avoid loss of control, skidding, and fishtailing.

ESC automatically activates when it detects that the driver is losing control of the car, correcting any oversteer and understeer that the driver may be committing under stress and panic. The vehicle's onboard computer will apply individual brakes to one or more of the four wheels to help bring the car back on the driver's intended direction.

History of ESC

Although anti-skid systems have been around since the early '80s, it wasn't until 1992 when the version of ESC as we know it came to be. Parts maker Bosch and tire company Continental are credited with its development. Working with BMW, the partnership developed a system that decreases engine torque to prevent loss of control during tricky road situations. From there, other car manufacturers began developing their own versions of the ESC.

In 2007, the European Union made it mandatory for all new vehicles to have ESC as standard. Australia followed suit by signing a similar law in 2009, although the mandatory rule only took full effect in 2013.

How does ESC work?

ESC relies on a series of sensors to detect the direction of the vehicle, position of the steering wheel, the speed at which you're going, etc. The system uses these metrics to detect any loss of control, after which it then automatically applies the brakes to the relevant wheel, which allows you to go back to your intended path.

ESC helps the driver:

• Correct any oversteering or understeering mistakes
• Improve handling and traction on slippery and treacherous roads
• Stabilize the car during sudden maneuvers

For example, if the system detects understeer as you veer to the right, it will apply the brakes to one or two inner wheels--the ones on the right--to tighten the vehicle's radius. In case of oversteer, it will brake one or both of the outside wheels. In extreme cases, ESC can also reduce the engine power and keep the car from speeding, even when the driver is stepping on the accelerator.

Although there are many versions of the technology, they all perform one basic function: to respond accordingly once loss of control is detected.

How to keep your car's ESC working properly

To ensure your ESC is always in tiptop shape, make sure your anti-lock braking system (ABS) is working effectively, as problems with your ABS can render ESC ineffective. Also, make sure that your tires are properly inflated and in good condition. Likewise, have your brakes checked regularly and address any issues immediately.