Electronic Stability Control (ESC) helps prevent a vehicle from skidding - and the driver from losing control of their vehicle - when cornering, braking sharply or making a sudden manoeuvre. ESC technology automatically activates the brakes to help steer the vehicle in the correct direction. Electronic Stability Control (ESC) works with the vehicles' Anti-lock Braking System (ABS) to provide more traction and control. This system works by monitoring the wheels' rotational speed and watching for a loss of traction or control.
When it detects a loss of traction, it can reduce engine power or even apply the brakes slightly to try to give the driver more control. ESC helps prevent the car from "spinning" or "jackknifing" due to loss of traction on the road. In addition, ESC has a control unit that tracks the angle of the car's steering wheel, along with the rotation around the vehicle's vertical axis. This technology cannot increase traction on the road, but it helps you keep the car under control during extreme manoeuvres.
As the tyres now have grip, rather than slipping, you can also steer the vehicle if it helps to avoid a collision, which is not possible if the wheels are locked and slipping. The system is very effective, and Transport Canada studies suggest a 29% reduction in collisions caused by drivers losing control because of it. In some cases, the esc light comes on if your car is actively trying to maintain traction control. To help you get out of it, it uses some or all of the components of the ABS and traction control systems, including targeted wheel braking and engine power reduction to bring everything back in line with the direction of the wheels, and the driver back in control of the vehicle.
Comparatively, run-off, sometimes called understeer, can occur when a driver enters a corner while accelerating or braking, and the front wheels lose control due to reduced traction from ice, oil or other road conditions. It reduces the risk of losing control of your car when making sharp turns or emergency steering manoeuvres. Anti-lock brakes do the same thing, but electronically apply and release much faster than any driver can, helping to keep the vehicle stable when stopped. However, be aware that the ESC light may be an indicator that you are driving on a slippery road, and you may need to slow down to improve your control.
Stability control uses components and sensors from some of the vehicle's other safety features, including anti-lock brakes (ABS). If one of the wheels spins faster, which may indicate that you are on a slippery surface, the traction control system will activate the brake on that wheel, and may also momentarily reduce engine power, helping the spinning wheel to regain its grip. Figures vary depending on which survey you consult, but electronic stability control can help reduce single-car crashes (caused by loss of control in adverse or freak weather conditions) by between 25% and a third of the time. You may see it advertised with terms such as Vehicle Stability Assist (Acura), AdvanceTrac (Ford), StabiliTrak (General Motors) or Vehicle Dynamic Control (Nissan), among others.