Electrical Load Signal
WARNING: This page is about a different car, the 1996 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
An input signal is delivered to ELS1 and ELS2 terminals of Engine Control Module (ECM) to indicate when high electrical output is required. This signal is delivered when items such as rear window defroster, headlights, etc. are turned on. The ECM uses input signal to maintain proper idle speed.