PT Cruiser L4-2.4L (2008)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C High Pressure Switch
Description
DESCRIPTION
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).
Operation
OPERATION
The contacts in the A/C high pressure switch open and close causing the powertrain control module (PCM) or the engine control module (ECM),
depending on engine application, to turn the A/C compressor clutch on and off See: Compressor HVAC/Compressor Clutch/Description and
Operation/Operation. This prevents A/C compressor operation when the discharge pressure approaches high levels, and also reduces electrical surging
from A/C clutch engagement.
The A/C high pressure switch controls the electric cooling fan operation by monitoring refrigerant line pressures. When the discharge pressure rises
above 1900 to 2200 kPa (280 to 320 psi) the fan will turn on. The cooling fan will turn off when the discharge pressure drops to 1600 kPa (235 psi).
The A/C high pressure switch contacts open when the A/C discharge line pressure rises above 3100 to 3375 kPa (450 to 490 psi). The A/C high pressure
switch contacts close when the A/C discharge line pressure drops to 1860 to 2275 kPa (270 to 330 psi).
The A/C high pressure switch is factory-calibrated and cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
