* Faulty ABS Wheel Speed Sensor: This is the most frequent culprit. These sensors monitor wheel speed, and a malfunctioning sensor will trigger the light. They can become damaged from rust, debris, or simply wear out over time. Each wheel has a sensor.
* Bad ABS Control Module (PCM): The module is the "brain" of the ABS system. A failing module can cause a variety of problems, including the ABS light staying on.
* Low Brake Fluid: While less likely to cause a *steady* light (it often blinks if low), extremely low brake fluid could be a contributing factor, especially if it's linked to a leak in the system which is also affecting other components.
* Wiring Issues: Damaged or corroded wiring within the ABS system can disrupt signals and trigger the light. This is often related to age and exposure to the elements.
* Faulty ABS Pump Motor: The pump is part of the hydraulic system that activates the ABS. A malfunctioning pump will likely trigger the light.
* Problems with the tone ring (ABS ring): Located on the wheel hub, this component interacts with the wheel speed sensor. Damage or corrosion to it can interfere with the sensor's reading.
What to do:
1. Don't ignore it: Driving with a steady ABS light means the ABS system isn't functioning. While you can still brake, you lose the anti-lock functionality, potentially leading to wheel lockup in an emergency stop.
2. Check your brake fluid level: Make sure it's within the normal range. Low fluid points to a leak somewhere in the brake system that needs immediate attention.
3. Get it diagnosed: The most reliable way to identify the problem is to have a professional mechanic or auto parts store (many offer free diagnostic checks) scan the vehicle's OBD-II system. This will provide trouble codes that pinpoint the likely cause. Attempting to fix this yourself without proper tools and knowledge could lead to further damage or incorrect repairs.
Without a proper diagnostic scan, any attempt at fixing the issue is likely to be a shot in the dark and potentially costly. A professional diagnosis will save you time and money in the long run.
