What Is Traction Control? What Is Stability Control?
When your tires lose grip, these driver aids step in to keep you on the road and moving forward.
Shutterstock
Article QuickTakes
Traction control and stability control are two of the oldest and arguably most important computer-controlled driver aids. Both help you maintain control of a vehicle when the tires lose grip or can’t find traction, but in different ways. Here’s an explainer of what these systems do and how they work for your benefit.
What is Traction Control?
When you’re accelerating on a slippery surface and the vehicle detects wheelspin (i.e., the tire is moving more quickly than it should given the speed of the car), traction control attempts to mitigate the slip by applying slight brake pressure to the misbehaving wheel and/or reducing the engine output. For instance, say you’re looking to turn onto a busy street in the rain. There are only a few small breaks in traffic, so you need to enter the road swiftly. If your vehicle doesn’t have traction control and you accelerate hard, the drive wheels may slip on the wet surface instead of propelling you forward. Unless you ease up on the accelerator, the vehicle will accelerate slowly or may not move at all. With traction control, though, the vehicle senses the slip and slows the rotation of the drive wheels enough so that your car can find traction and turn the engine’s output into forward motion.
What is Stability Control?
Stability control—also known as electronic stability control (ESC), dynamic stability control (DSC), and vehicle stability control (VSC)—works similarly to traction control, but it is designed to stop a car from spinning or skidding. When a car is driving straight, stability control may intervene to keep the front of the car pointed down the road. In a turn, stability control can work to keep a vehicle on the intended trajectory.
Imagine you’re on a cloverleaf ramp to the expressway and your car loses traction. It’s obvious to you that your car isn’t going to make the turn, but when you crank the steering wheel further, your car keeps plowing towards the outside of the curve. Pulling data from yaw, steering-wheel-angle, and wheel-speed sensors, the stability-control system determines that you want to keep turning and, thus, applies slight brake pressure to an inside wheel and/or reduces the engine power to keep your car on the road and moving in its intended direction.
Should I Ever Disable Traction or Stability Control?
If you find yourself stuck in sand, snow, or mud, it may be helpful to disable traction control. In these scenarios, letting the tires spin a little may help the car find traction and claw out of the mire. This situation is common enough that most vehicles with traction or stability control systems have a dedicated button to disable most, or all, of the functions. Otherwise, the only time you’d want to turn off either traction or stability control is if you’re attempting to embrace your inner race car driver and driving in a controlled environment, such as at a racetrack. These systems exist to help drivers avoid a collision or compromising situation, and they work wonders.
