Circuit/System Description
WARNING: This page is about a different car, the 2012 GMC Yukon XL and 2012 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
The wheel speed sensor receives 12 V reference from the electronic brake control module (EBCM) and provides a DC square wave signal back to the module. As the wheel spins, the EBCM uses the frequency of the square wave signal to calculate the wheel speed.