Circuit/System Description
WARNING: This page is about a different car, the 2017 Cadillac ATS. However, it is still accessible from the selected car via links, so may be relevant.
The wheel speeds are detected by active wheel speed sensors. The tone ring consists of permanent magnets. Each wheel speed sensor receives signal voltage from the electronic brake control module and provides an alternating current square wave signal to the electronic brake control module. As the wheel spins, the electronic brake control module uses the frequency of the high and low signals to calculate the wheel speed.