Taillight Relay Circuit: Description
WARNING: This page is about a different car, the 2007 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.
When the light control switch, located on the headlight dimmer switch, is turned to the TAIL position, the taillight relay (Marking: T-LP) turns on to illuminate the front side marker lights, rear taillights, side marker lights and license plate light.