What is an ABS magnetic ring?

In the world of automobiles, the ABS magnetic ring plays the role of a "detector." It's an indispensable small part of the anti-lock braking system (ABS), and although inconspicuous, it's crucial for driving safety.

↳ What does it do?

Speed ​​"translator": The main function of the ABS magnetic ring is to work with sensors to tell the car's computer how fast each wheel is rotating.
Prevents skidding: When you brake hard, if a wheel suddenly stops rotating (locks up), the computer detects the anomaly through this magnetic ring and automatically releases the brake slightly to prevent the car from losing control and skidding.

↳ What does it look like? Where is it located?

Appearance: It's usually a circular ring, looking like a black rubber ring or a toothed metal ring. Modern cars mostly use magnetic rubber material, with a smooth surface, but the inside is densely packed with positive and negative magnetic poles invisible to the naked eye.
Location: It is generally installed on the wheel bearing, at the end of the driveshaft, or directly integrated into the wheel hub bearing seal.

↳ How does it work?

Magnetic scanning: Just like a barcode scanner in a supermarket, when the wheel rotates, the ABS magnetic ring also rotates.
Signal generation: The nearby sensor detects the changes in the magnetic field generated as the magnetic ring rotates and converts these changes into electrical signals that are sent to the computer. The faster the wheel rotates, the faster the signal changes.

↳ Common problems and maintenance

Dirt interference: Because it's close to the ground, the ABS magnetic ring easily attracts iron filings and mud. If it's too dirty, the sensor "can't see" the signal clearly, and the ABS light on the dashboard will light up.
Damage and failure: If the magnetic ring is cracked or its magnetism weakens, it can lead to misjudgment by the braking system, and even cause the brake pedal to inexplicably jump during low-speed braking.
Cleaning method: Rinsing the inside of the wheel hub during car washing is helpful, but if the light comes on, it usually requires a repair shop to clean it with a special cleaning agent, or directly replace the damaged bearing unit.