Posted on 8/28/2026
An ABS warning light can come from something as simple as one bad wheel-speed signal or something deeper inside the hydraulic control unit. From the driver's seat, those failures can look almost identical. The ABS light comes on, traction control may shut off, and the regular brakes can still feel completely normal. That is where testing becomes important. A trouble code can point us toward one wheel or toward the ABS itself, but we still need to find out whether the sensor, wiring, bearing, or control module is actually responsible. What the Wheel Speed Sensors Are Doing Wheel speed sensors tell the ABS computer how fast each wheel is rotating. During braking, the module watches those signals for a wheel that is slowing much faster than the others. If it sees one approaching lockup, it can quickly adjust hydraulic pressure at that wheel. Traction control uses much of the same information. That is why one faulty sensor signal can turn on several warning lights ... read more