Circuit/System Description

The wheel speeds are detected by active wheel speed sensors. Each wheel speed sensor receives a ignition 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 square wave signal to calculate the wheel speed. The electronic brake control module sends the wheel speed information as a high speed controller area network (CAN) serial data message.

Some modules connected to the high speed CAN bus monitor for the wheel speed information. This DTC is set when the wheel speed information has not been validated. The radio receives the vehicle speed signal from the electronic brake control module in order to correlate actual vehicle speed to the movement of the vehicle calculated by the navigation system.