The amber ABS fault light is illuminated on a vehicle's instrument panel. The vehicle contains a four channel permanent magnet sensor ABS brake system. All of these are true except.
Permanent magnet sensors and companion tone rings produce a AC frequency converted to DC pulses by the ABS controller.
Permanent magnet sensor systems function well at speeds below 5 mph.
Oversized tires will have an adverse effect on this ABS system.
The gap between the sensor and the tone ring is critical with PM sensor operation.