Circuit Description
WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
The pressure switch sends the appropriate signals to the intgration control and panel when the A/C refrigerant pressure drops too low or rises too high. When the integration control and panel receives these signals, it outputs signals via the integration control and panel to switch OFF the compressor relay and turns the magnetic clutch OFF.