Touch Select High-Low Switch
WARNING: This page is about a different car, the 2002 Toyota Tundra and 2001 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
Touch select high-low switch sends a request signal to the 4WD control ECU, which activates the transfer shift actuator. This switch is part of the integration and control panel, located in the front of the floor console.