Posted on 12/19/2025
When an ABS light pops on, it is easy to assume the whole anti-lock system is failing. In many cases, though, the trouble comes down to just one wheel speed sensor. Even a single bad sensor can shut down ABS, traction control, and stability systems, and that is why the car feels so different on wet or slick roads when that light is on. What ABS Speed Sensors Actually Do Each ABS speed sensor sits near a tone ring or encoder at the wheel or hub. As the wheel turns, the sensor reads tiny changes in the magnetic or toothed ring and converts that movement into a speed signal. The ABS control module uses these signals to compare how fast each wheel is spinning, especially during braking. When all four sensors agree, the system can decide whether braking is smooth or a wheel is about to lock up. If one sensor suddenly shows the wrong speed, or no speed at all, the module can no longer trust the data, so it turns on the warning light and may disable ABS and related system ... read more