Many newer vehicles have antilock brakes, traction control and stability control and they all share some of the same parts and sensors. Stability control will be standard on all vehicles starting next year.
If a vehicle starts to fishtail (when the back of the vehicle is sliding out ahead of the rest of the vehicle), being able to apply brake pressure to the outer front wheel will help bring that vehicle back under control.
On the other hand, if the vehicle slides straight ahead when you are trying to turn, applying brake pressure to the rear wheel on the side that you are trying to turn to will help the vehicle turn in that direction. But as a driver, you can’t apply pressure to one wheel at a time and even if you could, you could never do it fast enough before you slide out of control.
That’s where the stability control system comes into play and there are several key parts to the system that all work together. There are speed sensors at each wheel, which continually send the wheel speed information to the stability control computer. Speed sensors such as these have been used on antilock brake systems for years.
Next is the steering angle sensor. It’s mounted along your steering column and it tells the computer what direction you are turning the steering wheel. That’s important because the control system needs to know what direction you’re intending to steer the vehicle, especially if the vehicle is going in a different direction.
The system also has a sensor that’s located right in the center of the vehicle, usually somewhere under the driver’s right elbow. This sensor can tell if the vehicle is starting to spin and in what direction.
Now that the computer has all of the readings from these sensors, it can figure out what needs to be done and gets to work. When a vehicle starts to slide out of control, the stability control system applies the brakes at certain wheels to keep the vehicle from spinning out. In some cases, the system even reduces power at the engine to bring the vehicle back under control.
If it sounds like the computer and control system are doing a lot of adjustments very quickly, they are. It’s all happening in milliseconds and most of the time the system kicks in and saves the day before you even realize what happened. Stay safe out there!