ABS light on
The buyer question: "ABS light on"
Arrange an inspection promptly. If the red brake warning light is also on, the pedal feels abnormal, braking is weak, or the car pulls, stop driving and arrange professional help.
What could cause it
More than one problem can cause the same symptom. These are places to inspect, not a diagnosis.
- A wheel-speed sensor or wiring fault
- Low brake fluid or a brake-system problem
- An ABS module, tone ring, or hydraulic-control issue
- A vehicle-specific fault stored by the brake control system
Safe things to check
Keep clear of moving parts, hot components, and traffic. Use the owner's manual for vehicle-specific instructions.
- Check which warning lights are on and read the owner's manual
- Look at the brake-fluid warning information without opening a hot system
- Do not assume the light is only a sensor because the vehicle still stops
Do not continue if the brake pedal is soft, braking is weak, the red brake light is on, or the car is unstable. Pull over safely and arrange a tow or qualified assessment.
What a mechanic may check
A technician may scan the ABS module, inspect sensors and wiring, check brake fluid and hydraulic operation, and test the system after repair.
If you are considering this car
An ABS light during a used-car viewing is an unresolved safety issue. Request a diagnostic scan and independent brake inspection before considering the car.
Questions for the seller
- When did the ABS light appear, and are any other brake or stability lights on?
- Has a wheel bearing, sensor, brake, or suspension part been replaced?
- Will the seller provide a scan report and written repair history?