Power Steering Pressure (PSP) Switch (3.0L 4V Only)
WARNING: This page is about a different car, the 2003 Mercury Sable and 2003 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
A power steering pressure (PSP) switch (3N824) is located on the power steering pressure hose. It sends a signal to the powertrain control module (PCM) (12A650) to increase idle speed for idling stability when power steering pump pressure increases above the set pressure value.