Turn Signal Light Circuit: Description
WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
Receiving the signal of the turn signal switch from the combination switch ECU, the body ECU turns the turn signal light on.
The driver side junction block ECU activates the flasher relay while the theft deterrent system gives the warning and turns on the turn signal light.