The ABS light on your car's dashboard is a warning that there is a problem with the Anti-lock Braking System. When this light is illuminated, your standard hydraulic brakes will still function, but the anti-lock feature—which prevents wheel lockup during hard braking—may be disabled. This means you need to have the system diagnosed by a professional as soon as possible to restore your vehicle's full safety capabilities.
This system uses wheel speed sensors at each wheel to monitor if a wheel is about to stop rotating and lock up. If the sensor detects an impending lockup, the ABS control module rapidly pulses the brakes, much faster than a human can, to maintain steering control. The most common triggers for the ABS light are a faulty wheel speed sensor, a damaged tone ring (the serrated ring the sensor reads), a blown fuse, or low brake fluid level in the ABS reservoir.
If the light comes on and stays on, it indicates a diagnosed fault. If it flashes, it usually means the ABS is actively engaged during braking. Here is a quick reference for potential causes:
| Potential Cause | Symptom / Typical Repair | Estimated Repair Cost Range |
|---|
| Faulty Wheel Speed Sensor | Light on, ABS inoperative, possible traction control off | $150 - $350 |
| Damaged Sensor Tone Ring | Light on, specific to one wheel | $200 - $500 |
| Blown ABS Fuse | Light on, complete system shutdown | $10 - $100 |
| Low Brake Fluid | Light on, check main brake fluid reservoir | Top-up cost only |
| Faulty ABS Module | Light on, often requires specialist repair | $500 - $1,200 |
While you can still drive the car, you should adjust your driving habits. Avoid aggressive braking and leave more following distance. Brake earlier and more gently than usual, as slamming on the brakes could cause the wheels to lock up, leading to a skid, especially on wet or icy roads.
