* ABS Sensor Issues: Even if the wheel bearings were replaced, the ABS wheel speed sensors themselves could be faulty. They might be damaged, dirty, improperly installed, or have a bad connection. The sensors are located near the wheel bearing and are easily damaged during a bearing replacement.
* ABS Sensor Wiring: The wiring harness to the ABS sensor can be damaged, corroded, or have broken wires. This is common due to age and wear, especially in areas exposed to road salt and moisture.
* ABS Control Module (Pump/Module): The ABS control module is the "brain" of the system. It could be malfunctioning, even if the other components are fine. This is a more expensive repair.
* Low Brake Fluid: While less likely after a brake job, low brake fluid can trigger the ABS light. Check your brake fluid reservoir.
* Air in the ABS System: Air in the ABS hydraulic lines can prevent proper operation and trigger the light. This requires bleeding the ABS system, which is more complex than bleeding regular brakes. A shop specializing in brake work needs to perform this.
* Faulty ABS Ring (Tone Ring): Located on the wheel hub, this ring provides the signal for the ABS sensor. It might be damaged or improperly seated. This is less likely if the bearing was replaced, but it's possible.
* Loose or Corroded Connections: Check all electrical connections related to the ABS system. Corrosion is common, especially in older vehicles.
What to do:
1. Have the ABS system scanned: Take your car to a mechanic or auto parts store that can scan the ABS system for trouble codes. This will pinpoint the exact problem. A generic OBD-II scanner might not read ABS codes; you may need a more specialized scanner.
2. Inspect the ABS sensors and wiring: Once you have the codes, carefully inspect the ABS sensors and their wiring harnesses for any damage, corrosion, or loose connections.
3. Check Brake Fluid: Ensure the brake fluid level is correct.
4. Professional Diagnosis: If you're not comfortable working on the ABS system yourself (it's more complex than regular brake work), take it to a qualified mechanic specializing in brake systems. Attempting DIY repairs without the proper knowledge can cause further damage.
Ignoring the ABS light is dangerous. The ABS system is a critical safety feature. Getting the issue diagnosed and fixed promptly is crucial.
