Electronic Stability Control (ESC)

An Explanation of the Safety Feature

General Motors Stabilitrak in action
Electronic stability control helps keep drivers from losing control under adverse conditions -- even in poor-handling vehicles like SUVs and pickups. Photo © General Motors

Electronic stability control (ESC) is a safety feature that detects and helps to prevent or recover from skids. ESC can help keep the driver from losing control of the car in a panic swerve or when driving on slippery roads.

Importance of ESC

A government study showed that ESC reduced single-vehicle crashes by 34% for cars and 59% for SUVs. The Insurance Institute for Highway Safety estimates that ESC reduces the risk of fatal single-vehicle wrecks by 56% and fatal multiple-vehicle crashes by 32%. Because of its proven effectiveness, the US Government mandated that all new cars starting with the model year 2012 be equipped with ESC.

How Electronic Stability Control Works

ESC uses sensors in the car, including wheel speed sensors, steering wheel position sensors, and yaw sensors, to determine which direction the driver wants the car to go, and compares that to which way the car is actually going. If the system senses that a skid is imminent or has already started — in other words, that the car is not going in the direction the driver is telling it — it will apply the brakes on individual wheels to bring the car back under control. Because the system can brake individual wheels, whereas the driver can only brake all four wheels at once, ESC can recover from skids that a human driver can't.

The Difference Between ESC and Traction Control

Traction control senses wheel slip, which is when the drive wheels break loose and spin and reduce engine power or applies the brakes to stop it. Traction control can prevent some types of skids, but it does not provide the same level of protection as ESC. Generally speaking, ESC programs have a traction control function, so while ESC can do the same job as traction control, traction control cannot do the same job as ESC.

ESC Does Not Prevent Loss of Control of the Vehicle

Even with ESC, it is still possible to lose control of the car. Excessive speed, slick roads, and excessively worn or improperly inflated tires are all factors that can reduce ESC's effectiveness.

How to Know When the ESC System Is Active

Every manufacturer's ESC system works a little differently. With some systems, you may feel the car change direction slightly or hear the chattering of the antilock brake system. Other systems apply so gently as to be nearly imperceptible. Most ESC systems have a warning light that flashes when the system is active. ESC is most likely to activate on slippery (wet, snowy or icy) roads, though driving quickly on curvy, hilly roads or hitting a bump while cornering may also trigger the ESC system. Some performance-oriented systems will allow a skid to develop before stepping in.

Performance Stability Control Programs

Some high-performance cars have ESC systems that are programmed to be more permissive, allowing the car exceed its limits of traction and actually skid a bit before the system steps in and recovers from the skid. Performance cars from General Motors, including the Chevrolet Camaro, Chevrolet Corvette, and Cadillac ATS-V and CTS-V, have multi-mode stability control systems that let the driver control the amount of intervention and protection.

Alternate Terms for ESC

Different manufacturers use different names for their electronic stability control systems. Some of these names include:

  • Electronic Stability Program (ESP)
  • StabiliTrak
  • Vehicle Stability Assist (VSA)
  • Vehicle Stability Control (VSC)
  • Vehicle Dynamic Control (VDC)
  • Dynamic Stability Control (DSC)
  • AdvanceTrac with Roll Stability Control