Vehicle Speed Sensor
WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
Vehicle speed sensor is mounted on transaxle. Sensor rotor shaft is driven by a gear on output shaft of transaxle. Vehicle speed sensor sends a 4-pulse signal to cruise control ECU for each shaft rotation. Cruise control ECU uses this pulse frequency to calculate vehicle speed.