Circuit Description
WARNING: This page is about a different car, the 2003 Lexus ES 300 and 2002 Lexus ES 300. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle speed sensor detects the rotation speed of the transmission output shaft and sends signals to the ECM. See Fig 1. The ECM determines the vehicle speed based on these signals. An AC voltage is generated in the vehicle speed sensor coil as the rotor mounted on the output shaft rotates and this voltage is sent to the ECM.