Vehicle Speed Sensor
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 1997 GMC Savana Special, 1997 GMC Savana Camper Special, 1997 GMC Savana, 1997 Chevrolet RV Cutaway, and 1997 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
Vehicle Speed Sensor (VSS) is mounted in transmission (2WD) or transfer case (4WD). VSS produces an AC signal with a frequency proportional to speed at which transmission output shaft rotates, which is also proportional to vehicle speed. This signal is then sent to vehicle speed sensor buffer.