Transmission Control Switch Circuit: Description
WARNING: This page is about a different car, the 2013 Toyota Camry. However, it is still accessible from the selected car via links, so may be relevant.
When the shift lever is in S and it is moved toward "-" or "+", it is possible to select different shift ranges (1st through 6th ranges).
Moving the shift lever toward "+" increases the shift range by one, and moving the shift lever toward "-" decreases the shift range by one.