Vehicle Speed Sensor
WARNING: This page is about a different car, the 2002 Toyota Land Cruiser, 2002 Lexus LX 470, 2001 Toyota Land Cruiser, and 2001 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
Vehicle Speed Sensor (VSS) signal is delivered to ECM by No. 1 and No. 2 vehicle speed sensors. See Figure. No. 1 vehicle speed sensor is driven by gear on transmission output shaft, and indicates actual vehicle speed. No. 2 vehicle speed sensor detects transmission output shaft RPM. Gear shift point and lock-up timing are controlled by ECM based on signals from No. 2 vehicle speed sensor and throttle position sensor.