Let’s cover the antilock brakes first. In the old days we used to stay in control on slick streets by pumping our brakes so we didn’t spin out. Now, the antilock brakes do the pumping for us automatically.
Antilock brakes are not designed to make you stop faster, they’re designed to prevent you from losing control when you hit the brakes on a slick street. The main reason you lose control is because one or more of your tires comes to a stop while the vehicle is still moving forward. That’s called a skid and a skidding tire does not give you much traction between your vehicle and the street.
The antilock brake system relies on speed sensors that are located near each wheel. Those sensors monitor the speed of the wheels and that speed information is then fed back to the computer for the antilock brakes.
If any of the speed sensors detects that a tire is about to come to a skid, the antilock system will release some of the brake pressure to that wheel so it won’t lock up (kind of like pumping the brakes in the old days). That keeps the tire rolling just a little bit, which gives your tires some traction and keeps you from spinning out.
Traction control makes you go in slippery conditions and it uses some of the same parts as the antilock brake system. The same speed sensors monitor the tires when you are trying to accelerate. If one of your drive wheels gets on ice or snow and that wheel begins to spin faster than the other drive wheel, the traction control system will apply some brake pressure to the wheel that is slipping. That diverts the engine power over to the wheel that has traction and you move forward.
Be aware ahead of time that when the traction control or the antilock brake system kicks in, you might hear a buzzing noise coming from under the hood and a warning light on the dash might flash off and on. The engine power might even be cut momentarily when the traction control kicks in, but don’t worry that’s just the two systems doing their jobs.