Switch-A/C High Pressure
WARNING: This page is about a different car, the 2007 Chrysler PT Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
The A/C high pressure switch (1) sends a signal to the powertrain control module (PCM) or the engine control module (ECM), depending on engine application, to control A/C compressor clutch engagement/disengagement and to control electric cooling fan operation.
The A/C high pressure switch is mounted at the rear of the A/C compressor. The PCM/ECM will disengage the A/C compressor clutch if the refrigerant system pressure exceeds 3100 - 3375 kPa (450 - 490 psi).