Fuel Injector Circuit [12/2013 - 11/2016]: Description
WARNING: This page is about a different car, the 2016 Toyota Highlander, 2015 Toyota Highlander, and 2014 Toyota Highlander. However, it is still accessible from the selected car via links, so may be relevant.
The fuel injector assemblies are located on the intake port. They inject fuel into the cylinders based on the signals from the ECM.