Auxiliary Coolant Flow Pump
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
An auxiliary coolant flow pump is used only on hybrid vehicles to improve engine coolant circulation at low engine speeds or when the engine is OFF.
For a complete explanation of the auxiliary coolant flow pump refer to DESCRIPTION AND OPERATION heating and ventilation in the Description and Operation portion .