Wheel Speed Sensors and Rings
WARNING: This page is about a different car, the 2006 Suzuki Verona. However, it is still accessible from the selected car via links, so may be relevant.
A wheel speed sensor is present at each wheel. The sensors transmit wheel speed information to the EBCM by means of a small AC voltage. The signal is transmitted to the EBCM through interface that can cause false or noisy wheel speed sensor input to the EBCM.