DTC P1574: ASCD Vehicle Speed Sensor: Description
WARNING: This page is about a different car, the 2011 Nissan Leaf. However, it is still accessible from the selected car via links, so may be relevant.
The VCM receives two vehicle speed sensor signals via CAN communication. One is sent from the electrically-driven intelligent brake unit, and the other is from the traction motor inverter (motor speed signal). The VCM uses these signals for ASCD control. Refer to "AUTOMATIC SPEED CONTROL DEVICE (ASCD): SYSTEM DESCRIPTION " for ASCD functions.