Circuit Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
As the wheels spin, each wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signals to calculate each wheel speed.