Sensor Rotors
WARNING: This page is about a different car, the 2002 Toyota Corolla, 2001 Toyota Corolla, and 2000 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
Visually inspect sensor rotor serrations for scratches, cracks, missing teeth, or warping. Replace front drive axle shaft or rear hub as necessary if rotor is damaged.