The ABS sensor is a vital part of a vehicle's ABS system, which helps prevent the wheels from locking up during braking, especially in emergency situations or on slippery road surfaces. Mounted at each wheel or sometimes integrated into the wheel hub assembly, the ABS sensor detects the rotational speed of the wheels. It continuously monitors the speed and sends this information to the ABS control module. When the system detects that a wheel is about to lock up, it modulates brake pressure to that wheel, allowing it to continue rotating while still providing effective braking. This helps maintain steering control and stability, reducing the risk of skidding or loss of control.