What Is an ABS Actuator?

Lori Kilchermann

The actuator on an anti-lock brake system (ABS) is known as an ABS actuator. This is an electronic device that receives a signal from the vehicle's computer to control the brake pressure so that the wheels will not become locked up. The computer monitors the signals on a vehicle's braking system several 100,000 times per second, in some cases. When the computer senses that a brake is beginning to lock up, the ABS actuator adjusts the brake pressure being applied to the wheel and prevents the wheel from locking.

The ABS actuator alternates the braking pressure on any given brake, thereby preventing the wheel from locking while braking.
The ABS actuator alternates the braking pressure on any given brake, thereby preventing the wheel from locking while braking.

Offered as an option on several models of vehicles sold worldwide, the anti-lock brake system is intended to avoid accidents related to wheels becoming locked as the brakes are being applied. The system is computer-controlled and functions very similarly to the old and outdated practice of manually pumping the brake pedal in slick or low-traction areas.

The ABS actuator alternates the braking pressure on any given brake, thereby preventing the wheel from locking. As a wheel locks, its braking effectiveness is reduced thousands of times as compared to a still-rolling wheel assembly. The computer of a vehicle equipped with an ABS actuator will typically assist the driver in the proper application of brakes in all types of weather and road conditions.

The first ABS systems were designed for aircraft and were subsequently fitted onto automobiles in the 1940s. While the original units were not well-received, advances and changes in the system changed customers' perceptions and improved safety records verified manufacturers' claims touting the safety of the system. On most vehicles equipped with an ABS system, the vehicle can still be operated when the ABS system is disarmed. The ABS is usually only called upon in the event of an emergency application of the braking system. In most situations, the vehicle is able to operate with a malfunction in the ABS actuator while maintaining full use of the braking system.

One of the leading reasons for the malfunction of an ABS actuator is simply not using the system often enough. Many manufacturers recommend applying the brakes very hard to employ the ABS components on an occasional basis. This application of the brakes causes all of the components in the ABS system to move and receive some form of lubrication. This lack of lubrication is commonly behind many of the failures in the system. The individual parts in the actuator are not lubricated if the brakes are not being sharply applied on an occasional basis.

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Discussion Comments


@Melonlity -- As I understand it, all new cars in the United States must have ABS as standard equipment. I believe that law kicked in around 2012. That is a good thing, too, because those are pretty much necessary.

The only exception, really, might be on lighter cars that don't work the braking system as hard. Still, I feel a lot better driving a car with ABS than without it as I tend to get things with too much horsepower and need some considerable stopping power from time to time.


Wait a minute. Just about all cars have ABS installed? I didn't even think that was an option any more. I figured that all cars were sold with that very necessary safety feature. Are there some that lack it?


You want to have some real fun? Apply those breaks hard to activate your ABS systems with your kids in the car. They'll complain, you'll laugh and it's all good fun.

Seriously, my dad used to slam on his breaks from time to time to work the system and that was before ABS. He swore that kept things functioning well. Perhaps the same logic applies with modern braking systems.

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