What does it mean when an ABS sensor makes noise?

If you notice unusual noises when braking while driving, this may be closely related to the operational status of the ABS sensors. Here are a few possible scenarios:

 ABS Pump and Solenoid Valve Self-Check Sound (Normal)

During vehicle start-up or emergency braking, the ABS system automatically performs a self-check. The rapid switching of the solenoid valves during this process will produce a buzzing or clicking sound, which is usually a normal functional check sound and part of the system's protection mechanism.

False Alarm Sound Due to Dirty Sensors (Abnormal)

If the sensing part of the ABS sensor is covered with mud, sand, or oil, the signal may be interfered with, causing the system to misjudge wheel slippage. In this case, the ABS system may make a "clicking" sound during sudden braking at low speeds or on dry roads, attempting to intervene.

Continuous Buzzing Sound Due to Pump Failure or Air Bubbles

When there are air bubbles in the ABS pump or the pump itself is damaged, the hydraulic adjustment process will be abnormal, causing the pump to emit a continuous buzzing sound, which may be accompanied by a risk of increased braking distance.

Abnormal Noise Caused by Poor Wheel Speed ​​Sensor Contact

If the gap between the ABS sensor and the ABS gear ring is too large or the installation angle is incorrect, the sensor may collect incorrect signals, causing the ABS ECU to issue incorrect commands, resulting in frequent solenoid valve operation and abnormal noise.